Rotary engines

ABSTRACT

A rotary engine of the oscillating rotor or &#39;&#39;&#39;&#39;cat-and-mouse&#39;&#39;&#39;&#39; type including a shaft with a pair of rotors each mounted for rotation with respect to the shaft and for oscillating rotation with respect to each other. The engine includes drive means having drive members reciprocable in response to oscillating rotation of the rotors with respect to each other, and means responsive to reciprocation of the drive members to cause rotation of the shaft.

United States Patent Inventor Harold A. McMaster 707 Riverside Drive, Woodville, Ohio 43469 Appl. No. 889,194 Filed Dec. 30, 1969 Patented July 27, 1971 ROTARY ENGINES 124 Claims, 15 Drawing Figs.

11.8. CI. 60/19, 91/498, 92/58, 417/380, 4 I 71392, 4 l 7/405, 418/35 Int. Cl ..F0lb 21/00, FOlc 9/00 Field of Search ..92/58; 60/6,

l4, l9, 53 B; 418/33, 36, 35, 37, 38; 123/18, 18 A; 417/393, 348, 380, 405, 364; 91/498 [56] References Cited UNITED STATES PATENTS 3,361,038 1/1968 Orlofi 92/58 Primary Examiner-Martin P. Schwadron Assistant Examiner-Allen M. Ostrager Attorney-Barnard, McGlynn & Reising ABSTRACT: A rotary engine of the oscillating rotor or catand-mouse" type including a shaft with a pair of rotors each mounted for rotation with respect to the shaft and for oscillating rotation with respect to each other. The engine includes drive means having drive members reciprocable in response to oscillating rotation of the rotors with respect to each other, and means responsive to reciprocation of the drive members to cause rotation of the shaft.

PATENIFH .1 P I lull 3,595,014

' sum 3 or 7 INVENTOR.

AT TORNEYS PATENYEB JUL 2 1 an SHEET E OF 7 VA NE 5201 TOP DEAD CENTER IOO-- a u 6 5 wmmmowa zoEmoQ wz O 6 We m9 In a 4 7 5 PO E N H v On. L -75 l I l l |i... 6 O 6 SHAFT ROTATION DEGREES Ma "TORNFYb ROTARY ENGINES This invention relates generally to rotary engines, and is particularly concerned with rotary engines of the type including a pair of rotors mounted for oscillating rotation with respect to each other, the rotors carrying vanes or pistons which travel in a toroidal chamber or cavity upon rotation of their respective rotors. The vanes of one rotor alternately approach and recedc from the vanes of the other rotor to produce intake, compression, power and exhaust strokes. Such engines are described generally in the Feb. I969 issue of Scientific American in an article entitled Rotary Engines" by Wallace Chinitz, and in the Dec. 1963 issue of Automobile Engineer in an article entitled Rotary Combustion Engines" by R. F. Ansdale, and are sometimes referred to as cat'andmouse" engines because the vanes alternately approach and recede from each other in the manner of a cat chasing a mouse.

Oscillating rotor, or cat-and-mouse rotary engines have not received acceptance to date due primarily to the inability to overcome the problems of excessive shock loads associated with the oscillating rotation of the rotors, and due to the difficulties associated with fabrication of such engines. One proposed engine of this type consists of an annular stator with a water cooling jacket formed with intake and exhaust ports. A drive shaft is rotatably mounted in the stator and a pair of rotors containing two vanes or pistons are mounted for oscillating rotation with respect to each other on the drive shaft. Cams on the drive shaft cooperate with the rotors to alternate ly drive and anchor the rotors relative to the stator. Large shock loads result from the alternate acceleration and deceleration of the rotors from an at-rest position, and a large amount of energy is dissipated by the abrupt starting and stopping of the rotors.

In other recently proposed arrangements, power is hydraulically transmitted from the oscillating vaned rotors to the drive shaft. lri one such proposed arrangement, the engine has a toroidal chamber formed by an outer jacket and by abutting ring members formed on a pair of vaned rotors. Each rotor has four power vanes or pistons, and a hydraulic oil chamber is formed between the abutting rings of the rotor and Ihe shaft of the engine. The power vanes of the respective rotors cooperate to define expansible and contractable gas chambers in the toroidal chamber. The engine shaft is provided with a symmetrical impeller having lobes located within the hydraulic chamber. Each of the rotors carries a hydraulic vane or piston located in the oil chamber, the hydraulic pistons being located on opposite sides of the impellar lobes. As the rotors are caused to oscillate with respect to each other by explosion of fuel in the gas chambers, their respective hydraulic vanes oscillate within the hydraulic oil chamber and alternately apply pressure to the lobes of the impeller to impart rotation to the drive shaft.

in another proposed engine of this type wherein power is transmitted to the output shaft of the engine hydraulically an oil chamber is formed within a ring concentric with the rotors of the engine. Each rotor is connected mechanically with a flywheel, the flywheel in turn being connected with the drive shaftthrough a drive spring. Each rotor includes two hydraulic vanes freely rotatable on the drive shaft, and each of the hydraulic vanes carry slide valves with a lost motion connec tion such that as the hydraulic vanes accelerate and decelerate due to oscillation of the rotors with respect to each other, the slide valves move alternately between trailing and leading positions relative to their respective oil or hydraulic vanes due to momentum. On a power stroke of one of the rotors, its associated oil vane is in registry with ports in the wall of the oil chamber so that oil can pass from one side to the other of the oil vane through ports controlled by the lost motion valve. in one position of the valves, the oil vanes are hydraulically locked together so that both rotors move with the same velocity. After moving a certain angular distance together,

fluid can move from one side to the other of the hydraulic vanes to permit the rotors to oscillate with respect to each other.

In all of the engines of this type proposed to date, extreme difficulty has been encountered in successfully overcoming the shock loads generated by the stop-and-go motionof the rotors, which in turn tends to impart a jerking motion to the engine shaft. To date, the prior art engines of this type can operate only at extremely low speeds. Consequently, the failure to properly handle the acceleration and deceleration forces generated by oscillation of the rotors has severely limited the practical use of this type of rotary engine to the extent that they offcr no advantages over reciprocating piston engines.

It is, therefore, an object of this invention to provide a rotary engine of the oscillating rotor, or cat-andmouse" type wherein the rotors oscillate with a smooth motion that brings the acceleration forces due to oscillation of the rotors within acceptable limits.

A further object of this invention is to provide an oscillating rotor, or cat-and-mouse rotary engine wherein the rotors of the engine oscillate with a substantially sinusoidal motion that greatly reduces and smoothes out. the acceleration forces generated by oscillation of the rotors.

A further object is to provide an oscillating rotor, or catand-mouse" rotary engine having a self-contained hydraulic drive system substantially reducing the number of moving mechanical parts normally associate-d with this type of engine and substantially reducing the moment of inertia of the vane rotor assemblies to reduce the inertial forces.

A further object is to provide an oscillating rotor, or catand-mouse rotary engine having a shaft with a pair of rotors each mounted for rotation with respect to the shaft and for oscillating rotation with respect to each other with drive means including at least one drive member reciprocable in response to oscillating rotation of the rotors with respect to each other and rotatable about the axis of the drive shaft during its reciprocation, with means responsive to reciprocation of the drive member to cause rotation of the shaft and to cause the reciprocating drive member to move in a sinusoidal path about the axis of the shaft.

Still another object lies in the provision of an oscillating rotor, or cat-and-mouse rotary engine wherein a pair of vaned rotors are each mounted for rotation with respect to the drive shaft of the engine and for oscillating rotation with respect to each other with hydraulically operated drive means including drive members that are reciprocable in response to oscillation of the rotors with a reaction member engaged by and respon' sive to the reciprocating drive members to impart rotation to the drive shaft and cause the reciprocating drive members to move in a sinusoidal path about the axis of the shaft, and wherein the rotors are hydraulically connected with the reciprocating drive members such that they oscillate with respect to each other in a smooth, sine wave fashion.

A further object is to provide a. rotary engine including means defining a hydraulic circuit with a cavity for hydraulic fluid connected in the circuit, a shaft rotatable in response to flow of fluid to and from the cavity in the hydraulic circuit, a pair of rotors each mounted for rotation with respect to the shaft and for oscillating rotation with respect to each other with means responsive to oscillating rotation of the rotors with respect to each other to cause flow of hydraulic fluid to and from the cavity to cause rotation of the shaft.

A still further object is to provide cat-and-mouse" rotary engine having a self-contained hydraulic circuit with a cavity for hydraulic fluid connected in the circuit, a pair of rotors each mounted for rotation with respect to the shaft and for oscillating rotation with respect to each other to cause flow of hydraulic fluid to and from the cavity, and drive means opera ble in response to flow of hydraulic fluid to and from the cavity to impart rotation to the engine shaft and at the same time to hydraulically force the rotors to oscillate with a smooth, sine wave motion with respect to each other.

v3 Still another object is to provide a rotary engine wherein combustiohoffuel can take place in an external chamber disconnected from the engine parts during combustion to reduce noise and stress on the engine components and wherein ignition is continuous to reduce pollution problems, the high pressure gases resulting from the ignition being admitted to the engine partsafter ignition.

'ln carrying out the foregoing and other objects, the present invention may be embodied in an engine having two rotors each having an identical set of gas vanes or pistons which oscillate relative to each other in an annular gas cavity. The vanes of one rotor oscillate relative to the vanes of the other rotor to successively provide intake, compression, ignition and exhaust strokes. The gas vanes of each rotor project radially outwardly from a mounting ring member into sliding, sealing engagement with the inner surface of an annular water jacket forming the stationary outer wall of the engine housing or stator portion. Projecting radially inwardly from the mounting ring of each rotor are oil vanes, or hydraulic vanes, each of which forms a radial extension or continuation of a corresponding gas vane. Each rotor is supported on the drive shaft for rotation with respect to the drive shaft and with respect to each other about the axis of the drive shaft. For example, the inner peripheries of the hydraulic vanes may project into a sliding, sealing engagement with the outer periphery of the engine drive shaft to rotatably support the respective rotors on the drive shaft. Alternatively, the inner ends of the hydraulic vanes may be secured to inner ring members which in turn are rotatably supported in the drive shaft. The two rotors are mounted on the drive shaft with their ring members in end-to-end abutting relationship between a pair of axially spaced annular end wall members. The end wall members may be defined by a pair of axially spaced flywheels, the

' flywheels each being fixed to the drive shaft. Each gas vane and each hydraulic vane extends the entire axial distance between the end wall members and has a sliding, sealing engagement therewith.

Each adjacent pair of gas vanes and each adjacent pair of hydraulic vanes cooperate to define the movable walls of an expansible gas chamber and hydraulic chamber, respectively. The gas chambers are defined by adjacent pairs of gas vanes, one vane from each rotor, in cooperation with the outer surfaces of the rings, the inner wall of the water jacket, and axi ally spaced end wall members which may be defined by the two flywheels, or by stationary, hollow end wall members projecting inwardly from the water jacket. The hydraulic chambers are defined by each adjacent pair of hydraulic vanes, one vane from each rotor, in cooperation with the inner surfaces of the rings, the outer surface of the drive shaft, and the two flywheels or other end wall members fixed to the shaft.

Each flywheel carries a plurality of radial cylinders, and each cylinder on each flywheel communicates hydraulically with one of the hydraulic chambers. A ball piston is reciprocally mounted in each of the cylinders so that it can reciprocate radially with respect to the axis of the drive shaft. The ball pistons engage the inner surface or track of a cam having a shape such that as a ball piston is forced radially outwardly from its cylinder, it reacts against the surface of the cam with a force having a tangential component which acts through the wall of the cylinder carrying the piston to cause the flywheels to rotate about the axis of the drive shaft relative to the cam to thereby transmit rotation to the drive shaft. The shape of the cam surface is such that each ball piston moves in a sinusoidal or wavelike path about the axis of the drive shaft. By sinusoidal path is meant that the ball pistons reciprocate between two extreme positions as they rotate about the axis of the drive shaft, and that the position of each ball piston along its path of reciprocation is a sine function of the angular position of the ball piston with respect to the axis of the drive shaft.

When two adjacent hydraulic vanes move toward each other, they squeeze oil into an associated pair of cylinders on opposite flywheels to force the balls in the two cylinders radially outwardly againstthe cam surface. The hydraulic chambers on either side are simultaneously enlarged due to the separation of the oilvanes forming their expansible walls to thereby permit oil to return form the cylinders with which the latter chambers are connected to permit their respective ball pistons to retract. The cylinders and balls are oriented with respect to the cam surfaces and hydraulic chambers such that as one of the pistons is forced radially outwardly by oil pressure, it has begun to move from a point on the camsurface located radially innermost with respect to the shaft toward a point on the cam surface located radially outermost with respect to the shaft, and the pistons on either side thereof are permitted to react as they move toward a point on the cam surface located radially inwardly toward the axis of the shaft. Thus, as one piston extends, its adjacent pistons retract a like amount and the volume remains constant.

In one embodiment of the invention each rotor is formed with four gas vanes and four hydraulic vanes. The gas vanes thus form eight gas chambers in the annular gas cavity, or two sets of four gas chambers, one set of which expands as the other set correspondingly contracts as the rotors oscillate with respect to each other. Two ignition devices communicate with the annular gas cavity at diametrically opposite locations, or at top dead center and bottom dead center locations. At the end ofa cycle of oscillation of the rotors to bring the vanes at their closest approach to fully contract one set of chambers and fully -expandthe other set of gas chambers, one of the contracted gas chambers communicates with one of 'the ignition devices, and a diametrically oppositely located contracted gas chamber communicates with the other ignition device.

The two sets of gas chambers alternately expand and contract as they rotate about the axis of the engine shaft with respect to the stator portion of the engine. Each gas chamber, and its associated hydraulic chamber, is contracted when it, or its radial centerline, is located at either ignition device or at a point located form either ignition device. Two intake ports are formed in the outer wall of the engine housing at diametrically opposite locations. The leading end of each intake port is located approximately 90 from one of the ignition devices. Similarly, two exhaust ports are formed in the outer wall of the engine housing at diametrically opposite locations in the quadrants adjacent to the intake ports such that each ignition device is located substantially 90 from the leading end of an intake port in one adjacent quadrant and is located substantially 90 from the trailing end of an exhaust port located in the opposite adjacent quadrant. The rotors rotate in a direction such that each chamber successively communicates with an intake port, an ignition device and an exhaust port. As a contracted chamber communicates with an intake port, it begins to expand and receive a charge of fuel through the intake port. After the chamber fully expands in the quadrant just ahead of an ignition device, the gas vane forming its trailing wall moves toward the gas vane forming the leading wall to compress the charge of fuel. As the chamber reaches its fully contracted condition, it comes into communication with the ignition device, whereupon the compressed fuel is ignited to cause the chamber to expand on a power stroke. As the chamber expands due to ignition of the fuel, the leading gas vane of the chamber sweeps past the leading end of the succeeding exhaust port to exhaust the burned fuel from the toroidal cavity. The identical situation exists at diametrically opposite locations in the annular combustion cavity. Thus, the two sets of vanes cooperate to define two diametrically opposed power chambers, two diametrically opposed compression chambers and two diametrically opposed intake chambers, depending upon their respective locations relative to the ignition devices and the intake and exhaust ports.

The simultaneous ignition of the two ignition devices causes expansion of the gases in the diametrically oppositely located power chambers, and the adjacent compression and exhaustion chambers correspondingly contract while the intake chambers expand with the power chambers. As a gas chamber defined between two gas vanes expands, the corresponding hydraulic chamber simultaneously expands permitting flow of oil from the pair of cylinders with which it is connected thereby permitting the pistons in these cylinders to retract. Conversely, as two gas vanes move toward each other, their corresponding hydraulic vanes also approach each other to squeeze oil into the pair of cylinders with which they are connected to force the respective pistons in these cylinders radially outwardly against the surface of the respective cams. Thus, as the two sets of vanes approach and recede from each other, oil is pumped into and out of alternate sets of the cylinders to drive the flywheels.

In another form of the invention, two external combustion chambers are provided at the diametrically opposite top dead center and bottom dead center locations in place of conventional ignition devices. The external combustion chambers are composed of, or are lined with, refractory material. The exter nal combustion chambers are not exposed to the cooling effects of the exhaust, intake and compression cycles and can, therefore, reach and remain at white-hot temperatures during operation of the engine. Each of the external combustion chambers has an inlet port located on one side of dead center and an outlet port located on the other side of dead center. As one of the contracting gas chambers approaches a dead center location, it communicates with the inlet port of the associated external combustion chamber to discharge compressed air from the gas chamber through the inlet port into the external combustion chamber. The inlet port is then closed by the forward movement of the trailing vane of the gas chamber as the gas chamber moves into dead center position. While the gas chamber is in the dead center position, fuel is injected into the external combustion chamber and the mixture of fuel and compressed air or gas is ignited while the gas chamber is in the dead center position and out ofcommunication with the external combustion chamber so that no fuel is admitted into the gas chamber defined by the space between the vanes. As the contracted gas chamber moves slightly past the dead center position, it communicates with the outlet port of the external combustion chamber and the white-hot, high-pressure gases are readmitted to the contracted gas chamber defined in the space between the adjacent vanes to cause the gas chamber to expand on a power stroke. With the external combustion chambers, the violence of the explosion is confined in the external chamber to reduce noise and stress on the engine components. Furthermore, the gases can be caused to swirl and mix with the fuel injected into the external combustion chamber.

The rotors each rotate continuously in the same direction while the engine is running. There is no stopping and starting, or reverse rotation, of either rotor. Oscillation of the rotors with respect to each other takes place due to one rotor increasing its angular velocity and the other decreasing its angular velocity relative to the drive shaft with each explosion, or set of explosions, in the gas cavity.

Other objects, advantages and features of the invention will become apparent from the following description taken in connection with the accompanying drawings in which:

FIG. 1 is an axial cross-sectional view of a rotary engine embodying the invention and taken on line 1-! of FIG. 3;

FIG. 2 is a transverse sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is a transverse sectional view taken on lines 33 of FIG. 1;

FIG. 4 is a sectional view taken on lines 44 of FIG. 1;

FIGS. 5a through 5i are schematic views illustrating the positions of certain parts of the engine of FIGS. 1-4 at successive stages of operation;

FIG. 6 is a graphical representation of the movement ofcertain parts of the engine of FIGS. 1-4 during successive stages of operation;

FIG. 7 is a view similar to FIG. 1 of another form of rotary engine embodying the invention; and

FIG. 8 is a sectional view taken on line 88 of FIG. 7.

With reference to FIGS. 1 through 4 of the drawings, the present invention is embodied in a rotary engine including a shaft 2; a pair of rotors 4 and 6 each mounted for rotation with respect to shaft 2 and for oscillating rotation with respect to each other; and drive means designated generally by reference numerals 8 and 9 including drive members 10 and ill reciprocable in response to oscillating rotation of rotors 4 and 6 with respect to each other, and means in the form of earns 12 and 13 responsive to reciprocation of drive members 10 and II, respectively, to cause rotation of shaft 2. Cams l2 and 13 have endless cam surfaces 14 and 15, respectively, reacting against the respective drive members 10 and ill to impart rotation to shaft 2 upon reciprocation of the drive members.

For example, as. drive member 10a reciprocatcs, it reacts against cam surface 14 to impart rotation to shaft 2. Shaft 2 is nonrotatable with respect to drive member 10a such that as the shaft rotates, the drive member 10 is carried around the axis of the shaft in the manner set forth in greater detail below. Drive member 10a reciproeates in a radial direction with respect to the axis of shaft 2 upon oscillating rotation of rotors 4 and 6 with respect to each other, and the configuration of the cam surface 14 is such that it causes the drive member 10a to move in a sinusoidal path as it rotates with shaft 2 about the axis of shaft 2.

With reference particularly to FIGS. .2 and 4, cams I2 and 13 are of identical configuration and are in phase with each other with respect to the axis of the shaft. Cam 12 is formed with circumferentially spaced lobes 16 projecting toward the axis of shaft 2 to define radially inwardly extending curved portions 18 on cam surface 14, and is formed with radially outwardly extending curved portions 20 joining the radially inwardly extending portions 18 of the lobes 16 such that the drive members 10a are radially extendable away from the axis of shaft 2 as it moves from a radially inwardly extending portion 18 onto the adjacent radially outwardly extending portion 20, and is radially retractable toward the axis of shaft 2 as it moves from a radially outwardly extending portion 20 to the adjacent radially inwardly extending portion 16 as the drive member 10a rotates about the axis of shaft 2.

Radially extending, open-ended cylinders 22 and 23 are nonrotatably mounted with respect to shaft 2, and the drive members 10 and 11 each comprise a piston received in the open end of one of the respective cylinders 22 and 23. Each piston in the illustrated embodiment is in the form of a spherical or ball piston received in the open end of the cylinders 22 or 23. For example, drive member 10a comprises a ball piston which is received in the open end of a cylinder 22a and proects therefrom into en a ement with cam surface 14. J g g The illustrated embodiment of the invention includes a hydraulic circuit having a cavity for hydraulic fluid designated generally by reference numeral 25. Cavity 25 is connected in the hydraulic circuit. Cylinders 22 and 23 are connected in the hydraulic circuit in hydraulic communication with cavity 25.

With reference particularly to FIG. 3, the illustrated engine includes means 28a, 30a which are responsive to oscillating rotation of rotors 4 and 6 with respect to each other to cause hydraulic fluid to flow from cavity 25 to cylinder 22a and thereby radially extend piston llOa relative to the axis of shaft number 2 as piston number 10a moves. past the innermost point of an inwardly extending portion 18 of cam surface 14. Means 28a and 30a are in the form of hydraulic vanes movable away from each other for permitting hydraulic fluid to return from cylinder 22a to cavity 25 as piston member moves past the radially outermost point of an outwardly extending portion 20 of cam surface 14 to cause the piston member 10a to radially retract relative to the axis of shaft 2 as it moves from the radially outermost point toward the following radially innermost point on the cam surface 14. Vanes 28a and 30a define the movable walls of an lexpansible and contractable chamber 321: in cavity 25 which is hydraulically connected with cylinder 22a. Thus, vanes 28a and 3011 are movable toward and away from each other in response to oscillating rotation of rotors 4 and 6 to respectively cause hydraulic fluid to flow to cylinder 22a to radially extend piston member a, and permit hydraulic fluid to flow from cylinder 220 into chamber 320 upon radial retraction ofpiston member 100.

Each one of the hydraulic vanes 28a and 30a is carried by one of the rotors, vane 28a being carried by rotor 4 and vane 30a being carried by rotor 6. Cavity is an annular and the shaft 2 extends axially through the cavity such that the outer surface of shaft 2 forms a inner cylindrical wall of the annular cavity 25. Each of the rotors is formed with a ring member having an inner diameter greater than the diameter of shaft 2 Rotor 4 has a ring member 34 and rotor 6 has a ring member 36. Ring members 34 and 36 are disposed in end-to-end relationship with each other and in concentric relationship with shaft 2 such that the inner surfaces of rings 24 and 26 define the outer cylindrical wall of cavity 25,

Cavity 25 is further enclosed by a pair of axially spaced end wall members 38 and 40 (FIG. I) nonrotatably mounted on shaft 2 and projecting radially therefrom. Each end wall member 38 and 40 abuts the outer end of one of the ring members to define an end wall of cavity 25. End wall member 38 abuts the outer end of ring 36, and the end wall member 40 abuts the outer end of ring members 34. Annular sealing members 38b and 40b are respectively mounted in the end wall members 38 and 40. End wall members 38 and 40 are thus in sliding, sealing engagement with the outer ends of the ring members 34 and 36, respectively.

Each of the hydraulic vanes 28a and 30a extends between the inner and the outer cylindrical walls of cavity 25 as well as between the end walls 38 and 40 of cavity 25 to form an expansible and contractable chamber 320 therewith. Cylinder 220 is carried by end wall 38, and a port 42a in the end wall 38, together with a recess 44a formed in the shaft 2, hydraulically connect chamber 32a with cylinder 22. Similarly, cylinder 23a is carried by the end wall member 40 and is connected through a port 43a in member 40 together with a recess a in shaft 2 with chamber 32a Consequently, cylinders 22a and 23a chamber 320, ports 42a and 43a, and recesses 44a and 45a cooperate to define a closed hydraulic system with pistons 10a and 11a defining movable walls of the closed hydraulic system and are radially extendable in response to contraction of chamber 32 a to correspondingly increase the volume of cylinders 22a and 23a subsequent expansion of chamber 320 permitting the pistons 10a and 11a to radially retract and correspondingly reduce the volume of cylinders 22a and 23a, respectively.

The illustrated engine has a housing or stator portion including a cylindrical water jacket having an outer cylindrical wall 48 and an inner cylindrical wall 49 which are concentric with the ring members 34 and 36 and the axis of shaft 2. The cylindrical wall 49 defines an annular gas cavity 50 with a ring members 34 and 36, the outer surfaces of ring members 34 and 36 defining the inner cylindrical wall of the annular cavity 50, and the inner surface of the cylindrical wall 49 defining the outer cylindrical wall of the annular cavity 50. The peripheral edges of the end wall members 38 and 40 extend into sliding, sealing engagement with the inner surface of the cylindrical wall 49 of the water jacket to define end walls for the annular gas cavity 50.

With reference particularly to FIG. 3, a pair of gas vanes 52a and 54a each project from ring members 34 and 36, respectively, and extend radially into sliding engagement with the inner surface of the cylindrical wall 49 of the water jacket, and extend axially between the end wall members 38 and 40 into sliding engagement with the end wall members 38 and 40. In a manner to be set forth in greater detail below, the gas vanes 52a and 5411 approach and recede from each other cyclically as rotors 4 and 6 rotate around the axis of shaft 2 to cause corresponding oscillating movement of the hydraulic oil vanes 28a and 30a to alternately contract and expand chamber 320. Thus, the gas vanes 52a and 54a associated with the oil vanes 28a and 30a cause the oil vanes 28a and 30a to alternately expand and contract chamber 280 to pump oil from chamber 320 into and out of the hydraulic cylinders 2211 and 23a associated with chamber 32a. As chamber 32a contracts, the associated pistons 10a and 11a are caused to radially extend against the surfaces 14 and 15 of earns 12 and 13, respectively. The forces exerted by pistons 10a and 11a against the respective cam surfaces 14 and 15 have a tangential component due to the configuration of the cam surfaces, which tangential components of force impart rotation to shaft 2 due to the engagement of pistons 10a and 11a with the walls of their respective cylinders 22a and 23a.

Basically, therefore, the illustrated engine of FIGS. 1-4 in cludes a pair of gas vanes 52a and 54a for providing power to expand and contract their associated hydraulic chambers 320, which expansion and contraction of chamber 32a causes extension and retraction, or reciprocation of at least one piston 10a, the cam surfaces 14 being responsive to and reacting with reciprocating pistons 10a to cause rotation of shaft 2. When the gas vanes 52a and 54a are caused to move away from each other by combustion of fuel in the annular cavity 50, oil can flow from cylinder 22a into the hydraulic cavity 25 and permits piston 10a to retract into cylinder 22a. Conversely, when the gas vanes 52a and 54a are caused to move toward each other by combustion of fuel in the annular cavity 50, oil is forced from the hydraulic cavity 25 into cylinder 22a to urge piston 10a to extend outwardly with respect to cylinder 22a. The reaction between piston 10a and cam 12 imparts rotation to shaft 2, and the configuration of the cam surface 14 is such that piston 10a moves in a sinusoidal path about the axis of shaft 2, and the gas vanes 52a and 54a approach and recede from each other in a smooth, sine wave fashion due to their hydraulic connection through the hydraulic vanes 28a and 30a with the motion of piston 10a. The acceleration forces normally encountered in rotary engines of this type are thus substantially reduced by the sinusoidal wave motion of the parts.

The acceleration forces are further reduced due to the fact that each of the rotors is formed with four gas vanes and four hydraulic vanes with the result that the rotors oscillate through a relatively small angle. Rotor 4 is formed with four gas vanes 52 located apart, and four corresponding oil or hydraulic vanes 28, also extending from ring 34 at right angles with respect to each other. Similarly,'rotor 6 has four gas vanes 54 extending outwardly from ring 36, and four hydraulic vanes 30 extending inwardly from ring 36, the gas vanes and hydraulic vanes being located 90 from each other.

The drive means of the illustrated embodiment includes eight drive members 10 which are designated in the drawing as 10a and 10h, and eight drive members 11 designated as 11a through 11h which are reciprocable in response to oscillating rotation of rotors 4 and 6 with respect to each other. The drive members 10 and 11 are each in the form of ball pistons engageable with surfaces 14 and 15, respectively, of earns 12 and 13, respectively. The cam surfaces react against the ball pistons and are thus responsive to reciprocation of the ball pistons to cause rotation of shaft 2.

Cam 12 has four circumferentially spaced lobes 16 projecting radially inwardly toward the axis of the shaft 2 to define four radially inwardly extending curved portions 18 on the cam surface 14. Cam 13 is of identical construction and is oriented with respect to shaft 2 in phase with cam 12. Cam 13 thus has four circumferentially spaced lobes l7 defining four radially inwardly extending curved portions 19 on cam surface 15. The radially inwardly extending curved portions 18 are joined by radially outwardly extending curved portions 20, and the radially inwardly extending curved portions 19 are joined by radially outwardly extending curved portions 21. Each of the drive members or pistons 10 and 11 is, therefore, extendable radially as it moves from a radially inwardly extending portion 18 or 19 onto the adjacent radially outwardly extending portion 20 or 21, respectively, and is radially retractable as it moves from a radially inwardly extending portion 20 or 21 to the adjacent radially inwardly extending portion 18 or 19, respectively, as the pistons are carried about the axis of shaft 2.

The drive members, or ball pistons, 10a through 10h are received in the open ends of cylinders 22a through 22h, respectively. Similarly, the ball pistons 11a through Illh are respectively received in the open ends of cylinders 23a through 23h. Pistons l and II project from the open ends of their respective cylinders into engagement with the respective cam surfaces 12 and 13. Pressure in the cylinders tending to radially extend the ball pistons and Ill outwardly from the axis of shaft 2 causes a reaction force between the ball piston and its respective cam surface, which reaction force has a tangential component of force, and the tangential component of force imparts rotation to shaft 2 due to the engagement of the ball pistons with the sidewalls of their respective cylinders, the cylinders being fixed relative to shaft 2. Cams l2 and 13 are contoured so that the centers of balls 10 and 11 follow a sine wave motion superimposed on a constant radius circle as the balls rotate around the axis of shaft 2 with a constant angular velocity with the shaft 2. With reference to FIG. 4, the centers of ball pistons 11a through 11h follow a sine 'wave motion superimposed on a constant radius circle Y shown in phantom lines as balls 11 reciprocate and simultaneously rotate about the axis of shaft 2.

. As shown in FIG. 1, cylinder 22a communicates hydraulically with cylinder 23a through cavity 25. Thus, cylinders 22a and 230 with their respective ball pistons 10a and Ila define a closed hydraulic circuit with cavity 25 through ports 42a and 43a and the associated recesses 44a and 45a formed in shaft 2.

Consequently, if hydraulic oil is forced from cavity 25 through the passages defined by ports 42a, 43a and recesses 44a, 45a, pistons 10a and 11a will be urged to extend radially with respect to the axis of shaft 2.Assuming clockwise rotation of shaft 2, cylinders 23 and pistons 11, as viewed in FIG. 4; as piston 11d moves past the radially innermost point indicated by the letter m of the curved portion 19 of lobe l7, hydraulic oil is forced from cavity 25 into cylinder 23d, as well as its associated cylinder 22d (FIG. 2), so that the reaction force between piston 1 Id and the surface of portion 19 to the left of point m in FIG. 4 has a tangential component of force which imparts rotation to shaft 2 through the engagement of piston 11d with the walls of cylinder-23d. The identical situation exists with the associated piston 10d and cylinder 22d in FIG. 2, except that the rotation is in the opposite, or counterclockwise direction as viewed in FIG. 2. As pistons llld and 10d continue to extend, piston 11d moves clockwise in FIG. 4 toward the following radially outwardly extending portion 21 until it is fully. extended as it reaches the radially outermost point indicated at n in FIG. 4. When piston lid is fully extended, it has moved from the position shown in FIG. 4 to point it on the radially outwardly extending portion 21 of cam surface 15, or the position of piston 11c illustrated in FIG. 4. As piston 11d continues to move clockwise past point n, the cam surface forces the piston to retract and decrease the volume of cylinder 23d available for the hydraulic oil. Consequently, the hydraulic oil displaced by retraction of piston Illd into cylinder 23d must return through ports 43d and recesses 45d to cavity 25. The same cycle or operation occurs with the corresponding piston 10d.

With reference to FIG. 3, rotor 4 is formed with four oil vanes 28a, 28b, 28c and 28d spaced 90 apart and extending radially inwardly from ring 34 of rotor 4. As illustrated in the embodiment of FIGS. I-4 the inner ends of the hydraulic oil vanes 28 are in sliding, sealing engagement with the outer surface of shaft 2. Similarly, rotor 6 is formed with four hydraulic vanes a, 30b, 30c and 30d extending radially inwardly from ring 36 with their inner ends in sliding, sealing engagement with the outer surface of shaft 2. Thus, rotors 4 and 6 are rotatably supported on shaft 2 by their respective oil vanes 28 and 30.

In the illustrated embodiment of FIGS. 1-4, the end wall members 38 and 40 constitute flywheels which are axially spaced on shaft 2 and which are fixed to shaft 2 so as to rotate with shaft 2. Ports 42a-42h and 43a-43h are respectively formed in flywheels 38 and 40 to provide communication llll between the respective cylinders 22a-22h and 23a23h and the hydraulic cavity 25. The periphery of flywheels 38 and 40 are provided with circumferential sealing members 38a and 40a, respectively, to provide a sliding, sealing engagement with the inner surface of the cylindrical wall 49 of the water jacket. Each of the hydraulic vanes 28 and 30 extends the full axial length between the inner surfaces of flywheels 38 and 40 and cooperate to divide the hydraulic cavity 25 into eight segmented chambers 32. Thus, the hydraulic vane 28a of rotor 4 cooperates with the hydraulic vane 30 of rotor s to define thcmovable walls of an expansible and contractable hydraulic chamber 32a. Chamber 320 communicates through ports 42a and 43a and the associated recesses 44a and 45a with cylinders 22a and 23a. Similarly, the hydraulic 28a cooperates with vane 30b to define a hydraulic chamber 32b communicating with cylinders 22b and 23b; vanes 30b and 28b define a hydraulic chamber 321? communicating through ports 42c, 43c and recesses 44c 450 with cylinders 22c and 231:, respectively, and so forth.

In the position of the rotors illustrated in FIG. 3, one set of hydraulic chambers including chambers 32a, 32c, 32e and 32g are in their collapsed or contracted conditions such that their corresponding pistons 10a, Illa, 10c, 110, 10c, 112, 10g and 11g are in their radially extended positions and engage the radially outermost points of the respective radially outwardly extending curved portions 20 and 21 of the cam surfaces. The other set of hydraulic chambers including chambers 32b, 32d, 32f and 32h are in their expanded positions and their respective pistons 10b, 1112, NM, 1111, 10f, 11f, 10h and 11h are consequently retracted and engage the radially innermost extending points of the inwardly extending curved portions 18 and 19 of the respective cam.

As hydraulic vanes 30a and 28d move toward each other, hydraulic oil is squeezed from chamber 32!: into cylinders 22h and 23h to urge pistons 10h and 11h to radially extend. Simultaneously, the adjacent chambers 32a and 32g on either side of chamber 32h expand as their respective walls 28a 30a and 28d, 30d move away from each other to permit their respective pistons 100, 11a and 10d, lid to retract toward the axis of shaft 2. Thus, as each chamber 32 contracts, causing the displaced oil to extend its associated pair of pistons 10 and 11, the adjacent chambers on either side of the contracting chamber correspondingly expand permitting their respective pistons 10 and 11 to retract and return the same volume of oil from the cylinders to the expanding chambers.

FIG. 2 illustrates the pistons 10 in a dead center position. As the assembly rotates from the position of FIG. 2, four of the pistons are constantly extending and the other four pistons are simultaneously retracting. Thus, as one piston extends, the adjacent pistons on either side of the extending piston correspondingly retract due to their engagement with the radially inwardly extending portion of the earn surface. Motion is thus transmitted to drive shaft 2 by the reaction between the pistons 10 and 11 with their respective cam surfaces 14 and 15. Each associated pair of cylinders 22 and 23 together with their respective pistons 10 and Ill cooperate with one of the chambers 32 to define a closed hydraulic system with the pistons defining movable walls of the closed hydraulic system which are radially extendable in response to contraction of the associated chamber 32 to correspondingly increase the volume of their respective cylinders, subsequent expansion of their associated chamber 32 permitting the pistons to radially retract and correspondingly reduce the volume of their respective cylinders.

With reference to FIG. 3, the outer surfaces of rings 34 and 36 cooperate with the inner surface'of wall 49 of the water jacket and the inner sufiaces of flywheels 38 and 40 to define an annular gas compartment or cavity 50 which is'divided into eight segmental gas chambers 'by adjacent pairs of the gas vanes 52 and 54. Gas vanes 52a and 54a cooperate to define the movable walls of an expansible gas chamber 55a Similarly, gas vanes 52a and 54b cooperate to define the movable walls of an expansible and contractable gas chamber hydraulic vane. For example, gas-vane 520 forms a radial extension of the hydraulic vane 28a, and the leading and trailing surfaces of a gas vane 52a lies in the same plane as the respective leading and trailing surfaces of the associated hydraulic vane 28a. Moreover, the leading and trailing surfaces of the gas vanes and hydraulic vanes lie in radial planes parallel with the axis of the shaft and diverging from each other from the axis of the shaft toward the outer cylindrical wall of compartment 50 defined by the inner surface of wall 49.

As illustrated in FIG. 3, gas chamber 550 is associated with the hydraulic chamber 32a in such a manner that the hydrau' lic chamber 320 is contracted when gas chamber 55a is retracted, and the hydraulic chamber 32a expands as the gas chamber 55a expands. Gas chambers 55b, 55d, 55e, 55f, 55g and 55h are similarly associated with the respective hydraulic chambers 32b-32h. It is apparent from FIG. 3 that if the gas vanes 54a and 52a are forced to separate by pressure in gas chamber 550 causing chamber 550 to expand, hydraulic chambers 32a, 32c, 32c and 32g will correspondingly expand along with their respective gas chambers 55c, 55c and 55g.

Conversely, the set of chambers including gas chambers 55b,

55d, 55f and 55h along with their respective associated hydraulic chambers 32b, 32d, 32f and 32h will correspondingly contract. Thus, the expansion of gas chambers 55a, 55c, 55c and 55g will be accompanied by retraction of pistons a, 110, 10c, 11c, 10c, lle, 10g and 11g; and will be accompanied by equal corresponding extension of pistons 10b,11b,10d,1ld,l0f, l1f,l0h,1lh.

Mounted in the cylindrical water jacket at top and bottom dead center locations with respect to the annular compartment 50 are ignition devices 64a and 64b which may be in the form of conventional spark plugs or glow plugs. Two intake ports 66a and 66b are formed in the stationary water jacket at diametrically opposite locations. Intake port 66a is located in the lower portion' of the upper right-hand quadrant as viewed in FIG. 3, intake port 66b is located in the upper portion of the lower left quadrant as viewed in FIG. 3. Similarly, a pair of exhaust ports 68a and 68b are formed in the outer wall of the engine housing at diametrically opposite locations. Exhaust port 68a is located in the upper portion of the lower right quadrant in FIG. 3 and is separated from intake port 660 by a partition 65. Exhaust port 68b is located in the lower portion of the upper left quadrant and is separated from intake port 66b by a partition 67. Assuming counterclockwise rotation of the vanes in FIGS. 3, each vane will first sweep past the ends of the exhaust ports 68a and 68b located furthest from the respective partition 65 and 67, and will then sweep past the intake ports 66a and 66b, respectively, from the ends of the intake ports located adjacent the respective partitions 65 and 67 to the ends of the intake ports located nearest the respective ignition devices 64a and 64b. Thus, the leading end of each intake port is located approximately 90 from one of the ignition devices, and the trailing end of each exhaust port is located approximately 90 on the opposite side of the respective ignition devices. Assuming that both rotors are rotating in a counterclockwise direction with respect to the shaft 2 and the stator portion of the engine as viewed in FIG. 3, as a gas vane 54 approaches a gas vane 52 in the upper left quadrant, the chamber defined by the approaching vanes 52 and 54 communicates with the exhaust port 68b, and any gases within the chamber 55 in the upper left quadrant will be expelled through the exhaust port 68b after the leading vane of the chamber sweeps past the leading end of the exhaust port 68b. A similar situation will occur in the lower right quadrant as viewed in FIG. 3 wherein the chamber 55 is defined by the approaching gas vanes 52 and 54 will expel its contents through,

the exhaust port 68a after the leading vane of the chamber sweeps past the leading end of exhaust port 68a, i.e., the end of exhaust port 680 located furthest from partition 65.

Starting from the dead center position shown in FIGS. 2, 3 and 4, the gas chambers 55a and 55e are both contracted and are in communication with the ignition plugs 64a and 64b, respectively. Gas chambers 55d and 55h are expanded and are in communication with the exhaust ports 68a and 68b, respectively. Gas chambers 55c and 55g are located just ahead of the leading ends of intake ports 66a and 66b, respectively, and just following the trailing ends of exhaust ports 68a and 68b, respectively. Gas chambers 55b and 55fare in communication with the the respective intake ports 56a and 56b with their trailing vanes 54b and 54d, respectively, approaching the trailing ends of the respective intake ports 66a and 66b Assuming that chambers 55a and 55e each contain a compressed charge of fuel, the compressed charges of fuel in chambers 55a and 55e will become ignited upon communication with the ignition plugs 64a and 64b, and the resulting pressure rise due to burning of the fuel will force the adjacent pairs of vanes 52a, 54a and 52c, 54c to separate with the result that chambers 55a and 55e will begin to expand on a power stroke.

As the rotors continue to rotate in a counterclockwise direction with respect to the stator and with respect to the rotating shaft 2, gas vanes 54a, 54b, 54c and 54d will begin to approach gas vanes 52d, 52a, 52b and 52c, respectively, to begin contraction of chambers 55h, 55f, 55d and 55b and corresponding expansion of chambers 550, 55g, 55c and 550. A charge of fuel will be received in chamber 55b through intake port 66a and as the trailing gas vane 54bof chamber 55b sweeps past the trailing end of intake port 66a and approaches the leading gas vane 52a of 55b, the charge of fuel will be compressed due to the resulting contraction of chamber 55b. The identical conditions exist simultaneously in chamber 55f Thus, as the chambers rotate counterclockwise in FIG. 3, about the axis of shaft 2 from the position shown in FIG. 3, chambers 55b and 55fwill begin to contract on a compression stroke.

Chambers 550 and 55g following chambers 55b and 55f, respectively, will begin to expand as they move counterclockwise from the FIG. 3 position. As the leading vanes 54b and 54d of chambers 55c and 55g, respectively, move past the leading ends of the respective intake ports 66a and 66b to bring chambers 55c and 55g into communication with the in take ports, the chambers will begin to receive a charge of fuel and thus start an intake stroke.

As the trailing surfaces of the leading gas vanes 52b and 52d of chambers 55d and 55h, respectively, sweep past the leading ends of the respective exhaust ports 68a and 68b, chambers 55d and 55h are exposed to exhaust and these chambers will thus begin an exhaust stroke and expel burnt gases contained therein through the exhaust ports as they contract from the position shown in FIG. 3.

Thus, as ignition occurs in the contracted chambers located at top and bottom dead center locations, one set of hydraulic chambers 32 is caused to expand and the other set of hydraulic chambers is caused to contract. In the FIG. 3 position, ignition of chambers 55a and 55e causes the set of hydraulic chambers including chambers 32a, 32c, 32c and 32g to expand, and the set of hydraulic chambers including chambers 32b, 32d, 32f and 32h are caused to correspondingly retract resulting in simultaneous radial extension of pistons 10 and 11b, 10d, 11a, 10f11f and 10h and 11f with corresponding radial retraction of pistons 10a, 11a, 10c, 11c, 10e, lle and 10g, 11g from their positions shown in FIG. 2. With each simultaneous explosion at top and bottom dead center of a contracted chamber in communication with the ignition plugs, oil is squeezed from one set of hydraulic chambers, namely the hydraulic chambers located angularly 45 on either side of the ignition devices, and this oil has nowhere to go except to force their associated pair of ball pistons 10 and 11 radially outwardly against the cams. The hydraulic chamber begins to contract as their associated ball pistons move past the point on the cam wherein the ball pistons are at their shortest radii, that is, the positions of ball pistons 10b, 11b, 10d, 11d, 10f, 11f, 10h and 11f in FIGS. 2 and 4. The slope of the cam surfaces with reference to the radius vectors of the ball pistons pro vides a tangential component of force forcing the balls against the sides of their respective cylinders to supply torque to the flywheels at eight points. Except for these useful power torques, all other forces are radially and tangentially balanced so that they cause no vibration or undue load on the main bearings ofthc shaft 2.

In the illustrated embodiment, the flywheels are each provided with eight pins 70a, 70b, 70c, 70d, 70e, 70f, 70g and 70h projecting, respectively, into gas chambers 55a through 55h. Pins 70 project from the flywheels to synchronize the rotors and maintain the adjacent pairs of hydraulic vanes 28 and 30 centered on the respective oil ports 42, 44 and recesses43, 45 at the nearest approach of the vanes. For example, pin 70a in FIG. 3 maintains vanes 28a and 30a centered with respect to ports 42a and 440 at the nearest approach of the gas vanes 52a and 540. After the engine is started, the vanes do not exert any net force against pins 70 to turn the flywheels, and the ad jacent pairs of vanes approach and recede from pins 70 in symmetrical sine wave fashion 180 out of phase so that there is no net torsional vibration imparted to the flywheels 38 and 40 as the flywheels rotate at a constant angular velocity.

Again referring to FIG. 1, shaft 2 is formed with reduced end portions 86 and 88 which are respectively rotatably received in bearing assemblies 90 and 92. Bearing assembly 90 is mounted in the engine housing outer end wall 94, and hearing assembly 92 is mounted in the engine housing outer end wall 96. End walls 94 and 96 are hollow to provide spaces 98 and 100, respectively, for water or other coolant. Similarly, the cylindrical water jacket has a space 102 defined between walls 48 and 49 for water.

Annular grooves 104 and 106 are formed respectively in end walls 94 and 96 which are respectively connected with oil inlet passages 108 and 110. Each cylinder 22 and 23 is formed with an inlet port 112 and 113, respectively, in communication with the respective grooves 104 and 106. Check valves 114 and 115 control ports 112 and 113, respectively. Hydraulic oil can, therefore, be constantly supplied through passages 108 and 110 to the hydraulic circuitry to compensate for leadage past the ball pistons. Additional oil is thus supplied to each cylinder at any time the pressure therein falls below the pressure in the respective grooves 104 and 106.

FIGS. a5i schematically show the positions of the gas vanes during 40 of rotation of the shaft and flywheels. In the illustrated embodiment, the vanes are nominally wide; that is, the leading and trailing surfaces of the vanes as viewed in FIG. 3, and as viewed in FIG. Sa-Si, diverge at an angle of ap' proximately 20. the vales are slightly less than 20' wide to allow room for compressed gas between adjacent pairs of the vanes. Consequently, two vanes occupy approximately 40 of the annular gas compartment 50 leaving 50 for working dis-- placement. An index radius for shaft 2 and the flywheels 38 and 40 passes through pin 700.

FIG. 5a illustrates the positions of the vanes at top dead center with the shaft and flywheel index radius passing through the top dead center position. Chambers $511,550, 55e and 55g are fully contracted, and chambers 55b, 55d, 55f and 55g are fully expanded. Chambers 55b and 55fare in communication with the intake ports, and chambers 55d and 55b are in communication with the exhaust ports. Chambers 550 and 556 each contain a compressed charge of fuel, while chambers 55c and 553 have just completed an exhaust stroke.

As ignition occurs simultaneously in chambers 55a and 55a to expand the charges of fuel therein, vane 54:: begins to move ahead of the index radius through pin 70a, and vane 52a begins to recede from the index radius. In FIG. 5b, the index radius has moved 5, and the leading surfaces of vanes 54b and 54d have moved past the trailing ends of the respective intake ports and compression of the fuel in chambers 55b and 55f begins. Chambers 55a and 55e are still undergoing a power stroke in FIG. 5b.

In FIG. 50, vane Sda has advanced 2.9 from the index radius and vane 520 has correspondingly receded 29 from lid the index radius, the index radius having advanced 10 from top dead center. Chambers 550 and 55s are still in a power stroke, and chambers 55b and 55f are still in a compression stroke. Chambers 550 and 55g are exposed to the intake ports, and chambers 55d and 55h are in communication with the exhaust ports.

Chambers 55a and 55e remain in a power stroke through slightly more than 35 rotation of the shaft and flywheel as illustratcdin FIG. 5h. As the trailing surface of vane 54a sweeps past the leading end of the exhaust port, the power stroke ends and chambers 55a and 55s begins an exhaust stroke. In FIG. 51', chambers 55!; and 55f are substantially fully contracted with a fresh charge of fuel and will communicate with the respective ignition devices with an additional 5 rotation of the shaft. Thus, each of the eight chambers receives an explosion as it passes each ignition device. Consequently, there are 16 power strokes per revolution of the shaft. The vanes of the respective rotors oscillate in symmetrical sine wave fashion relative to the shaft as indicated by the symmetrical relationship of the vanes relative to the index radius in FIG. 5a-5i.

FIG. 6 graphically illustrates the sinusoidal motion of the vanes relative to the flywheels and shaft 2. In FIG. 6 the shaft or flywheel rotation is indicated on the horizontal axis and the positions of the center lines of the vanes are shown on the vertical, or Y" axis. FIG. 5a, for example, shows the centerline of vane 54a at 10 beyond top dead center at 0 rotation of the index radius. Curve A on FIG. 6 shows the center line position of vane 54a relative to the flywheel index radius during rotation of the flywheel and shaft. Thus, after 10 rotation of the flywheel index radius, vane 54a has advanced to a position l2.9 ahead of the flywheel index radius, and vane 52a has receded to a position 12.9 behind the flywheel index radius. The mean position of vane 54a is 22.5" ahead of the flywheel index radius and the means position of vane 52a is 225 be hind the flywheel index point. Vanes 52a and 54a are 45 apart at 225 and 675 of rotation of the shaft, rotation of the flywheel index radius, and at each successive 45 on the graph. Each vane thus oscillates plus and minus -l2.5 about its mean position. Thus, at 0 shaft rotation, vane 54a is 12.5 behind this mean position, and vane 2 is 12.5 the head of its mean position. At 45 shaft rotation, the space between the vane centerlines is 70. The departure of each vane from its mean position is only approximately one-fourth of 50 result ing in a substantial reduction of the acceleration forces normally encountered with this type of engine.

The trigonometric equation for curve B of FIG, 6 is: Y= 2 2.5+ X+ cos 4 X". The general form of this equation ex' pressed in radians is: Y= 11/2N +0+D cos 40 where 6 is the angle X divided by 57.3, N is the total number of vanes on both rotors, and D is the displacement: angle. Differentiating to obtain the velocity: dy/d0=l 4D sin 49. Since sin 46 never exceeds 1, the velocity dy/dO is always positive if D is less than one-fourth radian or 57.3/4 =l4.3. In FIG. 6, D is 12.5 and hence the rotors always have a positive: velocity which means they never top their forward motion.

In the schematic views of FIGS. 5a through 51' the vanes are each 20 thick. Two such vanes occupy 40 of the combustion chamber leaving 50 for working displacement in each quadrant. Each set ofvanes oscillate only plus and minus l2.5 with respect to its mean position for every 45 of shaft rotation.

A four stroke combustion cycle occurs between each pair of vanes for each 180 of shaft rotation. There are two power strokes per chamber per revolution for a total of 16 power strokes per revolution of the shaft.

As the index radius of the shaft moves 45 from the position shown in FIG. 512, that is, as the shaft rotates 45, vane 541a moves forward 70 while vane 52a moves forward only 20. In the next 45 rotation of the shaft, the set of vanes 52a, b, c and d will rotate 70 while the set of vanes 54a, b, c and advance only 20. However, both sets of vanes continue to rotate in the same direction at all times. Neither set of vanes stops its counterclockwise rotation with respect to the engine housing, as

viewed in FIGS. a through 5i, but oscillate with respect to each other in a smooth sine wave motion.

In the form of the invention illustrated in FIGS. 7 and 8, parts corresponding to parts in the embodiment of FIGS. 1 through 4 are identified by the same reference numerals in creased by 100. Thus, rotors 104 and 106 in FIG. 7 correspond to rotors 4 and 6 in FIG. 1, respectively; rings 134 and 136 of FIG. 7 correspond respectively with rings 34 and 36 of FIG. 1; the annular gas cavity 150 of FIG. 7 corresponds to the annular gas cavity 50 of FIGS. l through 4; and so forth.

In the FIG. 1 embodiment, the end walls of the annular gas cavity 50 are defined by the flywheels 38 and 40. In the FIG. 7 embodiment, on the other hand, the end walls of the annular gas cavity 150 are defined by stationary annular end wall members 302 and 304 projecting radially inwardly from the inner surface 149 of the outer cylindrical wall 148. The annular end wall members 302 and 304 are secured to the outer cylindrical wall and are hollow to provide spaces 306 and 308. respectively, for coolant material. The outer cylindrical end surfaces of rings 134 and 136 are in sliding, sealing engage ment with the inner surfaces of the annular end wall members 302 and 304, respectively as well as with the respective flywheel members 140 and 138. Annular sealing members 310 and 312 are provided respectively on end wall members 306 and 308 for engaging the adjacent end walls of the rings 134 and 136, respectively. As in the previously described embodiment, members 138 and 140 define the end walls of the annular hydraulic cavity 125 in FIG. 7. Member 138 is provided with ports 1420 through h and 1430 through h, respectively, corresponding respectively with ports 42a through h and 43a through h in the embodiment of FIGS. I through 4.

Rotor 104 has an inner supporting sleeve 314 which is concentric with the mounting ring 134 and is secured to the inner ends of the hydraulic vanes 128a, b, c and d of rotor 104 corresponding respectively with the hydraulic vanes 280, b, c and d of the embodimen of FIGS. 1 through 4. Similarly, rotor 106 is provided with a supporting sleeve 316 secured to the inner ends of the hydraulic vanes 130a, b, c and d which correspond respectively with the vanes 130a, b, c and d of the embodiment of FIGS. 1 through 4. Sleeves 314 and 316 are disposed in end-to-end relationship and are rotatably supported on shaft 102. Thus, the inner abutting cylindrical ends of sleeves 314 and 316 are in sliding, sealing engagement with each other and the outer surfaces of sleeves 314 and 316 cooperate to define the inner cylindrical surface of the annular hydraulic cavity 125.

Cylindrical bearings 318 and 320 are fixed respectively to sleeves 314 and 316 and may be of bronze or similar material. lntemal annular grooves 322 and 324 are respectively formed in the adjacent or opposed ends of sleeves 314 and 316 and cooperate with each other to define an annular recess 326 between sleeves 314 and 316 and the outer surface of shaft 102. Mounted on sleeve 314 is a beveled ring gear 328 which projects into recess 326. A similar ring gear 330 is mounted on sleeve 316. The ring gears 328 and 330 mesh with pinion gears 332 rotatably mounted on pins 334 secured to and projecting radially from shaft 102. Thus, the ring gears 328 and 330 together with the pinion gears 332 interconnect the rotors 104 and 106 with shaft 102 to maintain the rotors and shaft in synchronization with each other as the rotors oscillate with respect to each other and rotate about the axis of shaft 102 in the identical manner of rotors 4 and 6 of the embodiment of FIGS. 1 through 4. With the gear means 328, 330 and 334, it is not necessary to provide pins 70 as in the previously described embodiment of FIGS. 1 through 4. In the embodiment of FIG. 7, the gear means 328, 330 and 334 provides a positive synchronization between rotors 104, 106, shaft 102 and the ball pistons 110 and 111. The gas vanes 152 and 154 as well as the hydraulic vanes 128 and 130 of the embodiment of FIG. 7 are forced by the gears 328, 330, and 332 to oscillate symmetrically with respect to the shaft and are thereby positively maintained in phase with the shaft at all times.

In the embodiment of FIG. 7, an external combustion chamber 340 is provided in a combustion housing 338a located at top dead center. A similar combustion housing 338b is located at bottom dead center, or at the diametrically opposed location with respect to the combustion housing 338a. The combustion chamber 340 may be refractory lined and can therefore remain at white-hot temperatures during operation .of the engine. The combustion chamber 340 communicates with the annular gas cavity through an inlet port 342 and an outlet port 344. The inlet port 342 and outlet port 344 communicate with the annular gas cavity 150 at circumferentially spaced locations as illustrated in FIG. 8. The inlet port 342 is located just ahead of the top dead center location as shown in FIG. 8 and the outlet port 344 is located just following the top dead center location.

Thus, as chamber a rotates about the axis of shaft 102 in a clockwise direction as viewed in FIG. 8, it communicates with the external combustion chamber 340 through the inlet port 342 as soon as the trailing end of the leading gas vane 152a passes the trailing edge of port 342 so that the air being compressed in chamber 155a is injected into the combustion chamber 340 through port 342. When chamber 155a reaches the top dead center location as shown in FIG. 8, the leading end of the trailing gas vane 1540 is past the leading or right end of port 342 to close port 342, and chamber 155a is shut off from communication with both ports 342 and 344. Thus, when the gas chamber 1550 is in the top dead center location, it is shut off from communication with the combustion chamber 340. At this time, combustion can take place in the combustion chamber with fuel injected externally into the white-hot chamber.

As soon as the gas chamber 155a moves slightly past the top dead center position as shown in FIG. 8, chamber 155a will communicate with the combustion chamber 340 through the outlet port 344. The white-hot pressure gases can then be readmitted to chamber 1550 through the outlet port 344. With the gas chamber 155a closed from the combustion chamber 340 at the top dead center location, the violence of the explosion is confined in the external chamber 340 to reduce noise and stress on the engine components. Furthermore, the gases can be caused to swirl and mix with the fuel injected externally into the combustion chamber 340 and no fuel will go into any of the gas chambers 155 between the respective gas vanes 152 and 154. The refractory lined chamber can remain white-hot to insure continuous ignition since chamber 340 does not get exposed to the cooling effects of the exhaust, intake and compression cycles.

Thus, FIG. 7 discloses a rotary engine comprising means defining an annular gas cavity 150 having an outer cylindrical wall 149; a shaft 102; a pair of rotors 104, 106 each mounted for rotation with respect to shaft 102 and for oscillating rotation with respect to each other. Gas vanes 152 and 154 are provided on each of rotors 104 and 106 and project into the annular gas cavity 150 such that an adjacent pair of gas vanes 152, 154 cooperate to define the movably walls of an expansible gas chamber 155. The adjacent pair of vanes 152 and 154 approach and recede from each other to respectively expand and contract the gas chamber 155 defined between the vanes in response to oscillation of rotors 104 and 106 with respect to each other as the rotors rotate about the axis of shaft 102 to respectively contract and expand the gas chamber 155 formed therebetween. An external combustion chamber 340 is carried by the engine and has an inlet port 342 and an outlet port 344 communicating with the annular gas cavity 150 at circumferentially spaced locations. Accordingly, each gas chamber 155 sequentially (l) communicates with the combustion chamber 340 when the space between the leading and trailing vanes 152 and 154, respectively, is in communication with the inlet port 342 only as the gas chamber 155 approaches its fully contracted condition, (2) is disconnected from the combustion chamber 340 when the trailing end of the leading vane 152 and the leading end of the trailing vane 154 are located between the inlet and outlet ports as the gas chamber reaches its fully contracted condition as shown in FIG. 8, and-(3) communicates with the combustion chamber 340 when the space 155 between the leading and trailing vanes 152 and 154, respectively, is in communication with the outlet port, 344 only as the gas chamber 155 begins to expand from its fully retracted condition.

While a specific form of the invention has been illustrated and described in the foregoing specifications and accompanying drawings, it should be understood that the invention is not limitedto the exact construction shown, but that various alternatives in the construction and arrangement of parts will become apparent to those skilled in the art without departing from the scope and spirit of the invention.

The embodiments of the invention in which I claim an exclu sive property or privilege are defined as follows:

1. A rotary machine comprising: a shaft; a pair of rotors each mounted for rotation with respect to said shaft and for oscillating rotation with respect to each other; and drive means including at least one drive member reciprocable in response to oscillating rotation of said rotors with respect to each other, and means responsive to reciprocation of .said drive member to cause rotation of said shaft.

2. A rotary machine as claimed in claim 1 wherein said means responsive to reciprocation of said drive member includes a cam having an endless cam surface reacting against said drive member to impart rotation to said shaft upon reciprocation of said drive member.

3. A rotary machine as claimed in claim 2 wherein said shaft is rotatable with respect to one of said drive member and cam, and is nonrotatable with respect to the other of said drive member and cam.

4. A rotary machine as claimed in claim 3 wherein said shaft is nonrotatable with respect to said drive member.

5. A rotary machine as claimed in claim 4 whereinthe configuration of the cam surface causes the drive member to move in a sinusoidal path as it rotates with said shaft about the axis of said shaft.

6. A rotary machine as claimed in claim 5 wherein said drive member reciprocates in a radial direction with respect to the axis of said shaft upon oscillating rotation of said rotors with respect to each other.

7. A rotary machine as claimed in claim 6 wherein the cam is formed with circumferentially spaced lobes projecting toward the axis of the shaft to define radially inwardly extending curved portions of the cam surface, said cam surface being formed with radially outwardly extending curved portions joining the radially inwardly extending portions of said lobes such that said drive memberis radially extendable as it moves from a radially inwardly extending portion onto the adjacent radially outwardlyextending portion, and is radially retractable as it moves from a radially outwardly extending portion to the adjacent radially inwardlyextending portion as the drive member rotates about the axis of said shaft.

8. A rotary machine as claimed in claim 7 wherein said drive means includes a radially extending open-ended cylinder nonrotatable with respect to said shaft, said drive member comprising a piston received in the open end of said cylinder and projecting therefrom into engagement with said cam surface.

9. A rotary machine as claimed in claim 8 wherein said drive means includes a hydraulic circuit having a cavity for hydraulic fluid connected in said circuit. said cylinder being connected in said circuit in hydraulic communication with said cavity.

10. A rotary machine as claimed in claim 9 further including an inlet passage for connecting said hydraulic circuit with a source of hydraulic fluid under pressure, and a valve operable to prevent flow of hydraulic fluid from said hydraulic circuit through said inlet passage but permit flow of hydraulic fluid into said circuit through said inlet passage when thepressure from the source exceeds the pressure in said circuit.

11. A rotary machine as claimed in claim 9 wherein said drive means includes means responsive to oscillating rotation of said rotors with respect to each other to cause hydraulic fluid to flow from said cavity to said cylinder to radially extend said piston member relative to the axis of said shaft as said piston member moves past the innermost point of an inwardly extending portion of the cam surface and for permitting hydraulic-fluid to return from said cylinder to said cavity as said piston member moves past the radially outermost point of an outwardly extending portion of said cam surface causing the piston member to radially retract relative to the axis of J said shaft as it moves from said radially outermost point toward the following radially innermost point on the cam surface.

12. A rotary machine as claimed in claim 11 wherein said means responsive to oscillating'rotation of said rotors with respect to each other comprises a pair of hydraulic vanes in said cavity defining the movable walls of an expansible and contractable chamber in said cavity hydraulically connected with said cylinder, said pair of hydraulic vanes being movable toward and away from each other in response to oscillating rotation of said'rotors to respectively cause hydraulic fluid to flow to said cylinder to radially extend said piston member and permit hydraulic fluidto flow from said cylinder into said chamber upon radial retraction of said piston member.

13. A rotary machine as claimed in claim 12 wherein each one of said pair of hydraulic vanes is carried by respective ones of said pair or rotors.

14. A rotary machine as claimed in claim 13 wherein said cavity is annular with an inner cylindrical wall and said shaft extends axially through said cavity.

15. A rotary machine as claimed in claim 14 wherein each 'of said rotors is formed with a ring member having an inner diameter greater than the diameter of said shaft, said rings being disposed in end-to-end relationship concentric with said shaft such that their inner surfaces define the outer cylindrical wall of said cavity.

16. A rotary machine as claimed in claim 15 including a pair of axially spaced end wall members nonrotatably mounted on said shaft and projecting radially therefrom and each abutting the outer end of one of said ring members to define an end wall of said cavity.

17. A rotary machine as claimed in claim 16 wherein each of said hydraulic vanes extends between the inner and outer cylindrical walls of said cavity as well as between the end walls of said cavity to form an expansible and contractable chamber therewith.

18. A rotary machine as claimed in claim 17 wherein said cylinder is carried by one of said end wall members, and including a port connecting said chamber with said cylinder such that said cylinder, chamber and port cooperate to define a closed hydraulic system with said piston defining a movable wall of said closed hydraulic system that is radially extendable in response to contraction of said chamber to correspondingly increase the volume of said cylinder.

19. A rotary machine as claimed in claim 13 including a cylindrical wall defining an annular gas cavity with said ring members, the outer surfaces of said ring members defining the inner cylindrical wall of said annular gas cavity.

20. A rotary machine as claimed in claim 19 including means forming end walls for said annular gas cavity.

21, A rotary machine claimed in claim 20 including a pair of gas vanes each projecting from respective ones of said ring members and extending radially into sliding engagement with the inner surface of said outer wall as well as axially between said gas cavity end walls into sliding engagement therewith.

22. A rotary machine comprising: a pair of axially spaced outer end walls; an outer cylindrical wall mounted between said outer end walls; a shaft rotatably mounted in said outer end walls; a pair of axially spaced end wall members nonrotatably mounted on said shaft and extending radially therefrom; a pair of rotors rotatably supported on said shaft and received between said end wall members, each rotor having a ring member with an identical set of hydraulic vanes projecting radially inwardly therefrom toward the axis of said shaft; and an identical set of gas vanes projecting radially outwardly from said ring into sliding engagement with the inner surface of said outer cylindrical wall, said ring members being disposed in end-to-end relationship with the outer annular end i of each ring member slidably engaged with the adjacent-end face of said outer cylindrical wall, said hydraulic vanes each extending axially into sliding engagement with said end wall members such that each adjacent pair of hydraulic vanes defines the movable walls of an expansible and contractable hydraulic chamber in said annular hydraulic cavity; and passage means communicating with each hydraulic chamber for delivery of fluid from the chamber upon contraction thereof caused by movement of the associated adjacent pair of hydraulic vanes toward each other, and for delivery of fluid to the chamber upon expansion thereof caused by movement of the associated adjacent pair ofvanes away from each other.

23. A rotary machine as claimed in claimZl further including an inlet passage for connecting said hydraulic cavity with a source of hydraulic fluid under pressure; and a valve operable to.prevent flow of hydraulic fluid from said hydraulic cavity through said inlet passage but permit flow of hydraulic fluid into said hydraulic cavity from said inlet passage when the pressure from the source exceeds the pressure in said hydraulic cavity.

24. A rotary machine as claimed in claim 22 wherein the leading and trailing surfaces of said gas vanes and hydraulic vanes lie in radial planes parallel with the axis of the shaft and diverging from each other from the axis of the shaft toward said outer cylindrical wall.

25. A rotary machine as claimed in claim 24 wherein the number of gas vanes of each rotor is the same as the number of hydraulic vanes of each rotor.

26. A rotary machine as claimed in claim 25 wherein each gas vane forms an extension of a hydraulic vane such that the leading and trailing surfaces of each gas vane lies in the same plane as the respective leading and trailing surfaces of the associated hydraulic vane.

27. A rotary machine as claimed in claim 22 further including drive means responsive to flow of fluid to and from said chamber for imparting rotation to said shaft. 4 I 28. A rotary machine as claimed in claim 27 wherein said drive means includes a plurality of piston members reciprocable in response to flow of hydraulic fluid to and from said chambers, and means responsive to reciprocation of said piston members to cause rotation of said shaft.

29. A rotary machine as claimed in claim 28 including a cylinder defined on each end wall member for each of said hydraulic chambers and communicating hydraulically with its associated hydraulic chamber through said passage means, and wherein said plurality of piston members is constituted by a piston reciprocably received in each of said cylinders.

30. A rotary machine as claimed in claim 29 wherein said means responsive to reciprocation of said piston members comprises a pair of cams located adjacent each end wall member and each having an endless cam surface reacting against the associated piston members to impart rotation to said shaft.

31. A rotary machine as claimed in claim 30 wherein the configuration of said cam surface causes the associated piston members to move in a sinusoidal, wavelike path during their rotation about the axis of said shaft.

32. A rotary machine as claimed in claim 31 wherein said cylinders are disposed on the respective end wall members to cause the pistons to reciprocate radially with respect to said shaft.

33. A rotary machine as claimed in claim 32 wherein each cam has a plurality of lobes projecting toward the axis of the shaft to define radially inwardly curved portions of the cam surface which are joined by radially outwardly extending portions such that each pistonmember is radially extendable as it moves from a radially inwardly extending portion onto the ad jacent radially outwardlyextending portion, and is retractable as it moves from a radially outwardly extending portion to the adjacent radially inwardly extending portion.

34. A rotary machine as claimed in claim 33 wherein each adjacent pair of vanes moves toward each other to contract the associated hydraulic chamber and deliver hydraulic fluid from the chamber to the associated pair of cylinders and cause the pistons therein to radially extend relative to the axis of the shaft as the pistons move past the radially innermost point of an inwardly extending portion of their associated cam surfaces, said adjacent pair of vanes moving away from each other to permit hydraulic fluid to flow into the chamber from the associated cylinders as the pistons therein move past the radially outermost point of an outwardly extending portion of their associated cam surface causing the pistons to radially retract relative to the axis of said shaft as said pistons move from said radially outermost point to the following radially innermost point on the cam surfaces.

35. A rotary machine as claimed in claim 34 wherein each rotor has four gas vanes such that adjacent pairs of gas vanes define pairs of diametrically disposed ignition chambers, exhaust chambers, intake chambers, and compression chambers in said annular gas cavity.

36. A rotary machine as claimed in claim'35 further including means for synchronizing the rotors to maintain each adjacent pair of vanes centered relative to their respective passages when the vanes are at their closest approach at the end ofa cycle of oscillation of the rotors.

37. A rotary machine as claimed in claim 36 wherein said last-named means comprises at least one pin projecting into one of said chambers from one of said end wall members.

38. A rotary machine as claimed in claim 36 wherein said last-named means comprises gears interconnecting said rotors.

and shaft.

39. A rotary machine as claimed in claim 22 further including a supporting sleeve mounted on the inner ends of each of said sets of hydraulic vanes for rotatably supporting each rotor in said shaft.

40. A rotary machine as claimed in claim 39 wherein each of said supporting sleeves is concentric with the ring member of its associated rotor, and said sleeves are disposed in end-toends relationship such that the outer surfaces of said sleeves define the inner surface of the annular hydraulic cavity.

41. A rotary machine as claimed in claim 40 further including an annular groove formed in the inner end of each of said sleeves such that the grooves of the abutting sleeves cooperate to form an annular recess; a ring gear carried by each sleeve in said recess; and at least one pinion gear carried by said shaft and projecting into said recess into engagement with said ring gears to maintain the rotors in synchronization with the shaft and each other.

42. A rotary machine comprising: means defining a hydrau-' lic circuit including a cavity for hydraulic fluid connected in said circuit; a shaft rotatable in response to flow of fluid to and from said cavity in said circuit; a pair of rotors each mounted for rotation with respect to said shaft and for oscillating rotation with respect to each other; and means responsive to oscillating rotation of said rotors with respect to each other to cause flow of hydraulic fluid to and from said cavity.

43. A rotary machine as claimed in claim 42 further including an inlet passage for connecting said hydraulic circuit with a source of hydraulic fluid under pressure, and a valve operable to prevent flow of hydraulic fluid from said hydraulic circuit through said inlet passage but permit flow of hydraulic fluid into said circuit through said inlet passage when the pressure from the source exceeds the pressure in said circuit.

44. A rotary machine as claimed in claim 42 wherein said means responsive to oscillating rotation of said rotors comprises a plurality of hydraulic vanes in said cavity movable relative to each other upon oscillation of said rotors to cause flow of hydraulic fluid to and from said cavity.

45. A rotary machine as claimed in claim M wherein said plurality of hydraulic vanes comprises two sets of hydraulic vanes, one of which is carried by one of said rotors and the other of which is carried by the other of said rotors.

46. A rotary machine as claimed in claim 45 further including a pair of radially projecting end wall members fixed to said shaft and spaced axially from each other and defining the end walls of said cavity.

47. A rotary machine as claimed in claim 45 wherein the hydraulic vanes cooperate to define a plurality of expansible and contractable chambers in said cavity with each adjacent pair of hydraulic vanes defining the movable walls of one of said chambers wherein oscillation of said rotors causes one set of said chambers to expand while the other set of said chambers correspondingly contracts.

48. A rotary machine as claimed in claim 47 further including means defining a passage for each of said chambers to conduct fluid flow to and from the chambers upon expansion and contraction, respectively, of the chambers.

49. A rotary machine as claimed in claim 48 wherein said means defining a passage for each of said chambers includes a port for each chamber in at least one ofsaid end walls.

50. A rotary machine as claimed in claim 48 further including drive means responsive to flow of fluid to and from said cavity to cause rotation of said shaft.

51. A rotary machine as claimed in claim 50 wherein said drive means includes at least one drive member reciprocable in response to fluid flow to and from said cavity, and means responsive to reciprocation of said drive member to cause rotation of said shaft.

52. A rotary machine as claimed in claim 50 wherein said drive means includes at least one drive member for each of said chambers reciprocable in response to fluid'flow to and from its associated chamber to cause rotation ofsaid shaft.

53. A rotary machine as claimed in claim 52 wherein said drive means further includes means responsive to reciprocation of said drive members for imparting rotation to said shaft.

54. A rotary machine as claimed in claim 53 wherein said means responsive to reciprocation of said drive members comprises a cam having an endless cam surface reacting against said drive members to impart rotation to said shaft upon reciprocation of said drive members.

55. A rotary machine as claimed in claim 54 wherein said shaft is nonrotatable with respect to said drive members such that the drive members rotate with the shaft.

56. A rotary machine as claimed in claim 55 wherein the configuration of said cam surface causes the drive members to move in a sinusoidal path and the drive members rotate with said shaft about the axis of said shaft.

57. A rotary machine as claimed in claim 56 wherein said drive members reciprocate in a radial direction with respect to the axis of said shaft upon oscillating rotation of said rotors with respect to each other.

58. A rotary machine as claimed in claim 57 wherein the cam is formed with circumferentially spaced lobes projecting toward the axis of the shaft to define radially inwardly extending curved portions of the cam surface, said cam surface being formed with radially outwardly extending curved portions joining the radially inwardly extending portions of said lobes such that said drive member is radially extendable as it moves from a radially inwardly extending portion onto the adjacent radially outwardly extending portion, and is radially retracta ble as it moves from a radially outwardly extending portion to the adjacent radially inwardly extending portion as the drive member rotates about the axis of said shaft.

59. A rotary machine as claimed in claim 58 wherein said drive members each comprise a piston, and including a plurality of open ended cylinders carried by a flywheel, each of said pistons being received in the open end of one of said cylinders and projecting therefrom into engagement with same cam surface.

60. A rotary machine as claimed in claim 59 wherein each of said cylinders communicates with the respective chambers through said ports whereby each piston is radially extendable in response to contraction of its associated chamber to correspondingly increase the volume of its cylinder, subsequent expansion of the associated chamber permitting the piston to radially retract and correspondingly reduce the volume of its cylinder.

61. A rotary machine as claimed in claim 42 wherein said shaft projects through said cavity and the inner wall of said cavity is defined by a surface concentric with said shaft.

62. A rotary machine as claimed in claim 61 wherein each rotor includes a mounting ring, the hydraulic vanes of each rotor projecting inwardly from the respective mounting ring to rotatably support the rotors on the shaft.

63. A rotary machine as claimed in claim 62 including a pair of radially projecting end wall members spaced axially from each other and defining the end walls of said cavity and wherein the mounting rings of said rotors are disposed in end toend abutting relationship with the outer end of one of said rings engaging one of said end walls and the outer end of the other of said rings engaging the other of said end walls such that the abutting rings define the outer cylindrical wall of said hydraulic cavity.

64. A rotary machine as claimed in claim 63 wherein the hydraulic vanes of each rotor extend the full axial distance between the end walls such that a hydraulic vane of one rotor cooperates with an adjacent hydraulic vane of the other rotor to define the movable walls of an expansiblc and contractable chamber.

65. A rotary machine as claimed in claim 64 including a port formed in at least one of said end walls in communication with said expansible and contractable chamber such that contraction of the chamber causes fluid to flow from said cavity through said port and expansion of said chamber permits return flow of fluid through said port.

66. A rotary machine as claimed in claim 64 wherein each of set of hydraulic vanes includes four hydraulic vanes extending inwardly from the respective rings with the hydraulic vanes of each set being spaced from each other on the respective ring and projecting radially inwardly toward the axis of the shaft, each hydraulic vane of one set lying in said cavity between a pair of hydraulic vanes of the other set.

67. A rotary machine as claimed in claim 62 wherein the hydraulic vanes cooperate to define eight segmental expansi' ble and contractable chambers in said cavity with each adjacent pairs of hydraulic vanes defining the movable walls of one of said chambers wherein oscillation of said rotors causes one set of four of said chambers to expand while the other set of four of said chambers correspondingly contracts.

68. A rotary machine as claimed in claim 67 further including means defining a passage for each of said chambers to conduet fluid flow to and from the chambers upon expansion and contraction, respectively, of the chambers.

69. A rotary machine as claimed in claim 68 wherein said means defining a passage for each of said chamber includes a port for each chamber in at least one of said end walls.

70. A rotary machine as claimed in claim 69 wherein said passage means further includes a recess in said shaft communicating with each of said ports.

71. A rotary machine as claimed in claim 46 wherein each rotor includes a mounting ring, the hydraulic vanes of each rotor projecting inwardly from the respective mounting ring.

72. A rotary machine as claimed in claim 71 including an outer cylindrical wall defining an annular gas cavity with said rings, the outer surfaces of said rings defining the inner cylindrical wall of said annular cavity.

73. A rotary machine as claimed in claim 72 including means defining axially spaced end walls for said gas cavity.

74. A rotary machine as claimed in claim 73 including a plurality of gas vanes projecting from each of said rings into sliding engagement with the inner surface of said outer cylindrical wall, each gas vanc extending axially into sliding engagement with the end walls.

75. A rotary machine as claimed in claim 74 wherein each rotor has a gas vane for each hydraulic vane, the gas vanes each forming a radial extension of a hydraulic vane, each gas vane of one rotor extending axially between a pair of vanes of the other rotor such that a plurality of expansible and contractable gas chambers are formed in the annular gas cavity with each adjacent pair of gas vanes defining the movable wall of one of said gas chambers.

76. A rotary machine as claimed in claim 74 further including means defining an external combustion cavity having an inlet port and an outlet port communicating with said annular gas cavity at circumferentially spaced locations such that each gas chamber sequentially (l) communicates with said combustion chamber through said inlet port, (2) is located between said inlet and outlet ports and is thereby disconnected from said combustion chamber, and (3) communicates with said combustion chamber through said outlet port as the rotors rotate about the axis of said shaft.

77. A rotary machine comprising: a rotatable shaft; a pair of rotors each mounted on said shaft for rotation with respect thereto; means defining a hydraulic circuit including a cavity for hydraulic fluid connected in said hydraulic circuit; drive means operable in response to flow of hydraulic fluid in said circuit to and from said cavity to cause rotation of said shaft; and means cooperable with said drive means and responsive to oscillation of said rotors with respect to each other as the rotors rotate about said shaft to cause hydraulic fluid to flow to and from said cavity.

78. A rotary machine as claimed in claim 77 further including an inlet passage for connecting said hydraulic circuit with a source of hydraulic fluid under pressure, and a valve operable to prevent flow of hydraulic fluid from said hydraulic circuit through said inlet passage but permit flow of hydraulic fluid into said circuit through said inlet passage when the pressure from the source exceeds the pressure in said circuit.

79. A rotary machine as claimed in claim 77 wherein said drive means includes at least one drive member reciprocable in response to fluid flow to and from said cavity, and means responsive to reciprocation of said drive member to cause rotation of said shaft.

80. A rotary machine as claimed in claim 79 wherein said means responsive to reciprocation of said drive member comprises an endless cam surface reacting against said drive member to impart rotation to said shaft upon reciprocation of said drive member.

81. A rotary machine as claimed in claim 80 wherein said shaft is nonrotative with respective to said drive member such that the drive member rotates with the shaft.

82. A rotary machine as claimed in claim 81 wherein the configuration of said cam surface causes the drive member to move in a sinusoidal path as the drive member rotates about the axis of said shaft.

83. A rotary machine as claimed in claim 82 wherein said drive member reciprocates in a radial direction with respect to the axis of said shaft in response to fluid flow to and from said cavity.

84. A rotary machine as claimed in claim 83 wherein the cam is formed with circumferentially spaced lobes projecting toward the axis of the shaft to define radially inwardly extending curved portions of the cam surface, said cam surface being formed with radially outwardly extending curved portions joining the radially inwardly extending portions of said lobes such that said drive member is radially extendable as it moves from a radially inward extending portion onto the adjacent radially outwardly extending portion, and is radially retractable as it moves from a radially outwardly extending portion to the adjacent radially inwardly extending portion as the drive member rotates about the axis of said shaft.

85. A rotary machine as claimed in claim 84 wherein said drive member comprises a piston, and including an open ended cylinder carried by said shaft with said piston being received in the open end of said cylinder and projecting therefrom into engagement with same cam surface.

86. A rotary machine as claimed in claim 85 wherein said cylinder is hydraulically connected with said cavity such that flow of fluid from said cavity to said cylinder urges the piston to radially extend, and return flow of fluid from said cylinder to said cavity permits the piston to radially retract.

87. A rotary machine as claimed in claim 86 wherein said means cooperable with said drive means and responsive to oscillation of said rotors to cause hydraulic fluid to flow to and from said cavity comprises at least one hydraulic vanev carried by each rotor and extending into said cavity such that the hydraulic vane of one rotor moves toward and away from the hydraulic vane of the other rotor in response to oscillation of the rotors to cause hydraulic fluid to flow to and from said cavity.

88. A rotary machine as claimed in claim 87 wherein said shaft projects through said cavity.

89. A rotary machine as claimed in claim 88 wherein each rotor includes a mounting ring, the hydraulic vane of each rotor projecting inwardly from the respective mounting ring toward the axis of said shaft.

90. A rotary machine as claimed in claim 89 further including a pair of flywheels fixed to said shaft and spaced axially from each other and defining the end walls of said cavity.

91. A rotary machine as claimed in claim 90 wherein the mounting rings of said rotors are disposed in end-to-end abutting relationship with the outer end of one of the rings engaging one of the flywheels and the outer end of the other ring engaging the other of the flywheels such that the abutting mounting rings define the outer cylindrical wall of said cavity.

92. A rotary machine as claimed in claim 91 including an outer cylindrical wall defining an annular gas cavity with said ring members, the outer surfaces of said ring members defining the inner cylindrical wall of said annular gas cavity.

93. A rotary machine as claimed in claim 92 including means forming a pair of axially spaced end walls for said gas cavity.

94. A rotary machine as claimed in claim 93 wherein said gas cavity end walls are hollow to provide space for coolant.

95. A rotary machine as claimed'in claim 93 including at least one gas vane projecting from each of said ring members into sliding engagement with the inner surface of said outer cylindrical wall, each gas vane extending axially into sliding engagement with the end walls.

96. A rotary machine comprising: a rotatable shaft; 21 pair of rotors each mounted for rotation with respect to said shaft; reciprocable drive members carried by said shaft and hydraulically connected with said rotors such that oscillation of the rotors with respect to each other causes reciprocation of the drive members; a reaction surface engaged by the drive members to provide a force to impart rotation to said shaft in response to reciprocation of said drive members and to constrain the drive members to move in a sinusoidal path about the axis of the shaft during rotation of the shaft, the hydraulic connection between the drive members and rotors constraining the rotors to oscillate with respect to each other with a symmetrical sine wave motion during rotation of the shaftv 97. A rotary machine as claimed in claim 96 further including means defining a cavity for hydraulic fluid, and means in said cavity carried by said rotors operable to cause hydraulic fluid to flow to and from said cavity and cause reciprocation of said drive members in response to oscillation of said rotors.

98. A rotary machine as claimed in claim 97 further including an inlet passage for connecting said hydraulic cavity with a source of hydraulic fluid under pressure; and a valve operable to prevent flow of hydraulic fluid from said hydraulic cavity through said inlet passage but permit flow of hydraulic fluid into said hydraulic cavity from said inlet passage when the pressure from the source exceeds the pressure in the hydraulic cavity.

99. A rotary machine as claimed in claim 97 wherein said means in said cavity carried by said rotors comprise a plurality of hydraulic vanes movable relative to each other upon oscillation of said rotors to cause flow of hydraulic fluid to and from said cavity. 

1. A rotary machine comprising: a shaft; a pair of rotors each mounted for rotation with respect to said shaft and for oscillating rotation with respect to each other; and drive means including at least one drive member reciprocable in response to oscillating rotation of said rotors with respect to each other, and means responsive to reciprocation of said drive member to cause rotation of said shaft.
 2. A rotary machine as claimed in claim 1 wherein said means responsive to reciprocation of said drive member includes a cam having an endless cam surface reacting against said drive member to impart rotation to said shaft upon reciprocation of said drive member.
 3. A rotary machine as claimed in claim 2 wherein said shaft is rotatable with respect to one of said drive member and cam, and is nonrotatable with respect to the other of said drive member and cam.
 4. A rotary machine as claimed in claim 3 wherein said shaft is nonrotatable with respect to said drive member.
 5. A rotary machine as claimed in claim 4 wherein the configuration of the cam surface causes the drive member to move in a sinusoidal path as it rotates with said shaft about the axis of said shaft.
 6. A rotary machine as claimed in claim 5 wherein said drive member reciprocates in a radial direction with respect to the axis of said shaft upon oscillating rotation of said rotors with respect to each other.
 7. A rotary machine as claimed in claim 6 wherein the cam is formed with circumferentially spaced lobes projecting toward the axis of the shaft to define radially inwardly extending curved portions of the cam surface, said cam surface being formed with radially outwardly extending curved portions joining the radially inwardly extending portions of said lobes such that said drive member is radially extendable as it moves from a radially inwardly extending portion onto the adjacent radially outwardly extending portion, and is radially retractable as it moves from a radially outwardly extending portion to the adjacent radially inwardly extending portion as the drive member rotates about the axis of said shaft.
 8. A rotary machine as claimed in claim 7 wherein said drive means includes a radially extending open-ended cylinder nonrotatable with respect to said shaft, said drive member comprising a piston received in the open end of said cylinder and projecting therefrom into engagement with said cam surface.
 9. A rotary machine as claimed in claim 8 wherein a hydraulic circuit having a cavity for hydraulic fluid connected in said circuit, said cylinder being connected in said circuit in hydraulic communication with said cavity.
 10. A rotary machine as claimed in claim 9 further including an inlet passage for connecting said hydraulic circuit with a source of hydraulic fluid under pressure, and a valve operable to prevent flow of hydraulic fluid from said hydraulic circuit through said inlet passage but permit flow of hydraulic fluid into said circuit through said inlet passage when the pressure from the source exceeds the pressure in said circuit.
 11. A rotary machine as claimed in claim 9 wherein said drive means includes means responsive to oscillating rotation of said rotors with respect to each other to cause hydraulic fluid to flow from said cavity to said cylinder to radially extend said piston member relative to the axis of said shaft as said piston member moves past the innermost point of an inwardly extending portion of the cam surface and for permitting hydraulic fluid to return from said cylinder to said cavity as said piston member moves past the radially outermost point of an outwardly extending portion of said cam surface causing the piston member to radially retract relative to the axis of said shaft as it moves from said radially outermost point toward the following radially innermost point on the cam surface.
 12. A rotary machine as claimed in claim 11 wherein said means responsive to oscillating rotation of said rotors with respect to each other comprises a pair of hydraulic vanes in said cavity defining the movable walls of an expansible and contractable chamber in said cavity hydraulically connected with said cylinder, said pair of hydraulic vanes being movable toward and away from each other in response to oscillating rotation of said rotors to respectively cause hydraulic fluid to flow to said cylinder to radially extend said piston member and permit hydraulic fluid to flow from said cylinder into said chamber upon radial retraction of said piston member.
 13. A rotary machine as claimed in claim 12 wherein each one of said pair of hydraulic vanes is carried by respective ones of said pair or rotors.
 14. A rotary machine as claimed in claim 13 wherein said cavity is annular with an inner cylindrical wall and said shaft extends axially through said cavity.
 15. A rotary machine as claimed in claim 14 wherein each of said rotors is formed with a ring member having an inner diameter greater than the diameter of said shaft, said rings being disposed in end-to-end relationship concentric with said shaft such that their inner surfaces define the outer cylindrical wall of said cavity.
 16. A rotary machine as claimed in claim 15 including a pair of axially spaced end wall members nonrotatably mounted on said shaft and projecting radially therefrom and each abutting the outer end of one of said ring members to define an end wall of said cavity.
 17. A rotary machine as claimed in claim 16 wherein each of said hydraulic vanes extends between the inner and outer cylindrical walls of said cavity as well as between the end walls of said cavity to form an expansible and contractable chamber therewith.
 18. A rotary machine as claimed in claim 17 wherein said cylinder is carried by one of said end wall members, and including a port connecting said chamber with said cylinder such that said cylinder, chamber and port cooperate to define a closed hydraulic system with said piston defining a movable wall of said closed hydraulic system that is radially extendable in response to contraction of said chamber to correspondingly increase the volume of said cylinder.
 19. A rotary machine as claimed in claim 18 including a cylindrical wall defining an annular gas cavity with said ring members, the outer surfaces of said ring members defining the inner cylindrical wall of said annular gas cavity.
 20. A rotary machine as claimed in claim 19 including means forming end walls for said annular gas cavity.
 21. A rotary machine claimed in claim 20 including a pair of gas vanes each projecting from respective ones of said ring members and extending radially into sliding engagement with the inner surface of said outer wall as well as axially between said gas cavity end walls into sliding engagement therewith.
 22. A rotary machine comprising: a pair of axially spaced outer end walls; an outer cylindrical wall mounted between said outer end walls; a shaft rotatably mounted in said outer end walls; a pair of axially spaced end wall members nonrotatably mounted on said shaft and extending radially therefrom; a pair of rotors rotatably supported on said shaft and received between said end wall members, each rotor having a ring member with an identical set of hydraulic vanes projecting radially inwardly therefrom toward the axis of said shaft; and an identical set of gas vanes projecting radially outwardly from said ring into sliding engagement with the inner surface of said outer cylindrical wall, said ring members being disposed in end-to-end relationship with the outer annular end of each ring member slidably engaged with the adjacent end wall member such that the inner surfaces of said rings defines the outer cylindrical wall of an annular hydraulic cavity receiving said hydraulic vanes, said annular hydraulic cavity having an inner cylindrical wall concentric with said shaft; the outer surfaces of said ring members defining the inner cylindrical wall of an annular gas cavity receiving said gas vanes, the outer cylindrical wall of which is defined by the inner surface of said outer cylindrical wall, said hydraulic vanes each extending axially into sliding engagement with said end wall members such that each adjacent pair of hydraulic vanes defines the movable walls of an expansible and contractable hydraulic chamber in said annular hydraulic cavity; and passage means communicating with each hydraulic chamber for delivery of fluid from the chamber upon contraction thereof caused by movement of the associated adjacent pair of hydraulic vanes toward each other, and for delivery of fluid to the chamber upon expansion thereof caused by movement of the associated adjacent pair of vanes away from each other.
 23. A rotary machine as claimed in claim 21 further including an inlet passage for connecting said hydraulic cavity with a source of hydraulic fluid under pressure; and a valve operable to prevent flow of hydraulic fluid from said hydraulic cavity through said inlet passage but permit flow of hydraulic fluid into said hydraulic cavity from said inlet passage when the pressure from the source exceeds the pressure in said hyDraulic cavity.
 24. A rotary machine as claimed in claim 22 wherein the leading and trailing surfaces of said gas vanes and hydraulic vanes lie in radial planes parallel with the axis of the shaft and diverging from each other from the axis of the shaft toward said outer cylindrical wall.
 25. A rotary machine as claimed in claim 24 wherein the number of gas vanes of each rotor is the same as the number of hydraulic vanes of each rotor.
 26. A rotary machine as claimed in claim 25 wherein each gas vane forms an extension of a hydraulic vane such that the leading and trailing surfaces of each gas vane lies in the same plane as the respective leading and trailing surfaces of the associated hydraulic vane.
 27. A rotary machine as claimed in claim 22 further including drive means responsive to flow of fluid to and from said chamber for imparting rotation to said shaft.
 28. A rotary machine as claimed in claim 27 wherein said drive means includes a plurality of piston members reciprocable in response to flow of hydraulic fluid to and from said chambers, and means responsive to reciprocation of said piston members to cause rotation of said shaft.
 29. A rotary machine as claimed in claim 28 including a cylinder defined on each end wall member for each of said hydraulic chambers and communicating hydraulically with its associated hydraulic chamber through said passage means, and wherein said plurality of piston members is constituted by a piston reciprocably received in each of said cylinders.
 30. A rotary machine as claimed in claim 29 wherein said means responsive to reciprocation of said piston members comprises a pair of cams located adjacent each end wall member and each having an endless cam surface reacting against the associated piston members to impart rotation to said shaft.
 31. A rotary machine as claimed in claim 30 wherein the configuration of said cam surface causes the associated piston members to move in a sinusoidal, wavelike path during their rotation about the axis of said shaft.
 32. A rotary machine as claimed in claim 31 wherein said cylinders are disposed on the respective end wall members to cause the pistons to reciprocate radially with respect to said shaft.
 33. A rotary machine as claimed in claim 32 wherein each cam has a plurality of lobes projecting toward the axis of the shaft to define radially inwardly curved portions of the cam surface which are joined by radially outwardly extending portions such that each piston member is radially extendable as it moves from a radially inwardly extending portion onto the adjacent radially outwardly extending portion, and is retractable as it moves from a radially outwardly extending portion to the adjacent radially inwardly extending portion.
 34. A rotary machine as claimed in claim 33 wherein each adjacent pair of vanes moves toward each other to contract the associated hydraulic chamber and deliver hydraulic fluid from the chamber to the associated pair of cylinders and cause the pistons therein to radially extend relative to the axis of the shaft as the pistons move past the radially innermost point of an inwardly extending portion of their associated cam surfaces, said adjacent pair of vanes moving away from each other to permit hydraulic fluid to flow into the chamber from the associated cylinders as the pistons therein move past the radially outermost point of an outwardly extending portion of their associated cam surface causing the pistons to radially retract relative to the axis of said shaft as said pistons move from said radially outermost point to the following radially innermost point on the cam surfaces.
 35. A rotary machine as claimed in claim 34 wherein each rotor has four gas vanes such that adjacent pairs of gas vanes define pairs of diametrically disposed ignition chambers, exhaust chambers, intake chambers, and compression chambers in said annular gas cavity.
 36. A rotary machine as claimed in claim 35 further including means for synchronizing the rotors to maintain each adjacent pair of vanes centered relative to their respective passages when the vanes are at their closest approach at the end of a cycle of oscillation of the rotors.
 37. A rotary machine as claimed in claim 36 wherein said last-named means comprises at least one pin projecting into one of said chambers from one of said end wall members.
 38. A rotary machine as claimed in claim 36 wherein said last-named means comprises gears interconnecting said rotors and shaft.
 39. A rotary machine as claimed in claim 22 further including a supporting sleeve mounted on the inner ends of each of said sets of hydraulic vanes for rotatably supporting each rotor in said shaft.
 40. A rotary machine as claimed in claim 39 wherein each of said supporting sleeves is concentric with the ring member of its associated rotor, and said sleeves are disposed in end-to-ends relationship such that the outer surfaces of said sleeves define the inner surface of the annular hydraulic cavity.
 41. A rotary machine as claimed in claim 40 further including an annular groove formed in the inner end of each of said sleeves such that the grooves of the abutting sleeves cooperate to form an annular recess; a ring gear carried by each sleeve in said recess; and at least one pinion gear carried by said shaft and projecting into said recess into engagement with said ring gears to maintain the rotors in synchronization with the shaft and each other.
 42. A rotary machine comprising: means defining a hydraulic circuit including a cavity for hydraulic fluid connected in said circuit; a shaft rotatable in response to flow of fluid to and from said cavity in said circuit; a pair of rotors each mounted for rotation with respect to said shaft and for oscillating rotation with respect to each other; and means responsive to oscillating rotation of said rotors with respect to each other to cause flow of hydraulic fluid to and from said cavity.
 43. A rotary machine as claimed in claim 42 further including an inlet passage for connecting said hydraulic circuit with a source of hydraulic fluid under pressure, and a valve operable to prevent flow of hydraulic fluid from said hydraulic circuit through said inlet passage but permit flow of hydraulic fluid into said circuit through said inlet passage when the pressure from the source exceeds the pressure in said circuit.
 44. A rotary machine as claimed in claim 42 wherein said means responsive to oscillating rotation of said rotors comprises a plurality of hydraulic vanes in said cavity movable relative to each other upon oscillation of said rotors to cause flow of hydraulic fluid to and from said cavity.
 45. A rotary machine as claimed in claim 44 wherein said plurality of hydraulic vanes comprises two sets of hydraulic vanes, one of which is carried by one of said rotors and the other of which is carried by the other of said rotors.
 46. A rotary machine as claimed in claim 45 further including a pair of radially projecting end wall members fixed to said shaft and spaced axially from each other and defining the end walls of said cavity.
 47. A rotary machine as claimed in claim 45 wherein the hydraulic vanes cooperate to define a plurality of expansible and contractable chambers in said cavity with each adjacent pair of hydraulic vanes defining the movable walls of one of said chambers wherein oscillation of said rotors causes one set of said chambers to expand while the other set of said chambers correspondingly contracts.
 48. A rotary machine as claimed in claim 47 further including means defining a passage for each of said chambers to conduct fluid flow to and from the chambers upon expansion and contraction, respectively, of the chambers.
 49. A rotary machine as claimed in claim 48 wherein said means defining a passage for each of said chambers includes a port for each chamber in at least one of said end walls.
 50. A rotary machine as claimed in claim 48 further including drive means responsive to flow of fluid to and from said cavity To cause rotation of said shaft.
 51. A rotary machine as claimed in claim 50 wherein said drive means includes at least one drive member reciprocable in response to fluid flow to and from said cavity, and means responsive to reciprocation of said drive member to cause rotation of said shaft.
 52. A rotary machine as claimed in claim 50 wherein said drive means includes at least one drive member for each of said chambers reciprocable in response to fluid flow to and from its associated chamber to cause rotation of said shaft.
 53. A rotary machine as claimed in claim 52 wherein said drive means further includes means responsive to reciprocation of said drive members for imparting rotation to said shaft.
 54. A rotary machine as claimed in claim 53 wherein said means responsive to reciprocation of said drive members comprises a cam having an endless cam surface reacting against said drive members to impart rotation to said shaft upon reciprocation of said drive members.
 55. A rotary machine as claimed in claim 54 wherein said shaft is nonrotatable with respect to said drive members such that the drive members rotate with the shaft.
 56. A rotary machine as claimed in claim 55 wherein the configuration of said cam surface causes the drive members to move in a sinusoidal path and the drive members rotate with said shaft about the axis of said shaft.
 57. A rotary machine as claimed in claim 56 wherein said drive members reciprocate in a radial direction with respect to the axis of said shaft upon oscillating rotation of said rotors with respect to each other.
 58. A rotary machine as claimed in claim 57 wherein the cam is formed with circumferentially spaced lobes projecting toward the axis of the shaft to define radially inwardly extending curved portions of the cam surface, said cam surface being formed with radially outwardly extending curved portions joining the radially inwardly extending portions of said lobes such that said drive member is radially extendable as it moves from a radially inwardly extending portion onto the adjacent radially outwardly extending portion, and is radially retractable as it moves from a radially outwardly extending portion to the adjacent radially inwardly extending portion as the drive member rotates about the axis of said shaft.
 59. A rotary machine as claimed in claim 58 wherein said drive members each comprise a piston, and including a plurality of open ended cylinders carried by a flywheel, each of said pistons being received in the open end of one of said cylinders and projecting therefrom into engagement with same cam surface.
 60. A rotary machine as claimed in claim 59 wherein each of said cylinders communicates with the respective chambers through said ports whereby each piston is radially extendable in response to contraction of its associated chamber to correspondingly increase the volume of its cylinder, subsequent expansion of the associated chamber permitting the piston to radially retract and correspondingly reduce the volume of its cylinder.
 61. A rotary machine as claimed in claim 42 wherein said shaft projects through said cavity and the inner wall of said cavity is defined by a surface concentric with said shaft.
 62. A rotary machine as claimed in claim 61 wherein each rotor includes a mounting ring, the hydraulic vanes of each rotor projecting inwardly from the respective mounting ring to rotatably support the rotors on the shaft.
 63. A rotary machine as claimed in claim 62 including a pair of radially projecting end wall members spaced axially from each other and defining the end walls of said cavity and wherein the mounting rings of said rotors are disposed in end-to-end abutting relationship with the outer end of one of said rings engaging one of said end walls and the outer end of the other of said rings engaging the other of said end walls such that the abutting rings define the outer cylindrical wall of said hydraulic cavity.
 64. A rotary machine as claimed in claim 63 wherein the hydraulic vanes of each rotor extend the full axial distance between the end walls such that a hydraulic vane of one rotor cooperates with an adjacent hydraulic vane of the other rotor to define the movable walls of an expansible and contractable chamber.
 65. A rotary machine as claimed in claim 64 including a port formed in at least one of said end walls in communication with said expansible and contractable chamber such that contraction of the chamber causes fluid to flow from said cavity through said port and expansion of said chamber permits return flow of fluid through said port.
 66. A rotary machine as claimed in claim 64 wherein each of set of hydraulic vanes includes four hydraulic vanes extending inwardly from the respective rings with the hydraulic vanes of each set being spaced 90* from each other on the respective ring and projecting radially inwardly toward the axis of the shaft, each hydraulic vane of one set lying in said cavity between a pair of hydraulic vanes of the other set.
 67. A rotary machine as claimed in claim 62 wherein the hydraulic vanes cooperate to define eight segmental expansible and contractable chambers in said cavity with each adjacent pairs of hydraulic vanes defining the movable walls of one of said chambers wherein oscillation of said rotors causes one set of four of said chambers to expand while the other set of four of said chambers correspondingly contracts.
 68. A rotary machine as claimed in claim 67 further including means defining a passage for each of said chambers to conduct fluid flow to and from the chambers upon expansion and contraction, respectively, of the chambers.
 69. A rotary machine as claimed in claim 68 wherein said means defining a passage for each of said chamber includes a port for each chamber in at least one of said end walls.
 70. A rotary machine as claimed in claim 69 wherein said passage means further includes a recess in said shaft communicating with each of said ports.
 71. A rotary machine as claimed in claim 46 wherein each rotor includes a mounting ring, the hydraulic vanes of each rotor projecting inwardly from the respective mounting ring.
 72. A rotary machine as claimed in claim 71 including an outer cylindrical wall defining an annular gas cavity with said rings, the outer surfaces of said rings defining the inner cylindrical wall of said annular cavity.
 73. A rotary machine as claimed in claim 72 including means defining axially spaced end walls for said gas cavity.
 74. A rotary machine as claimed in claim 73 including a plurality of gas vanes projecting from each of said rings into sliding engagement with the inner surface of said outer cylindrical wall, each gas vane extending axially into sliding engagement with the end walls.
 75. A rotary machine as claimed in claim 74 wherein each rotor has a gas vane for each hydraulic vane, the gas vanes each forming a radial extension of a hydraulic vane, each gas vane of one rotor extending axially between a pair of vanes of the other rotor such that a plurality of expansible and contractable gas chambers are formed in the annular gas cavity with each adjacent pair of gas vanes defining the movable wall of one of said gas chambers.
 76. A rotary machine as claimed in claim 74 further including means defining an external combustion cavity having an inlet port and an outlet port communicating with said annular gas cavity at circumferentially spaced locations such that each gas chamber sequentially (1) communicates with said combustion chamber through said inlet port, (2) is located between said inlet and outlet ports and is thereby disconnected from said combustion chamber, and (3) communicates with said combustion chamber through said outlet port as the rotors rotate about the axis of said shaft.
 77. A rotary machine comprising: a rotatable shaft; a pair of rotors each mounted on said shaft for rotation with respect thereto; means defining a hydraulic circuit including a cavity for hydraulic fluid connected in said hydraulic circuit; drive means operable in response to flow of hydraulic fluid in said circuit to and from said cavity to cause rotation of said shaft; and means cooperable with said drive means and responsive to oscillation of said rotors with respect to each other as the rotors rotate about said shaft to cause hydraulic fluid to flow to and from said cavity.
 78. A rotary machine as claimed in claim 77 further including an inlet passage for connecting said hydraulic circuit with a source of hydraulic fluid under pressure, and a valve operable to prevent flow of hydraulic fluid from said hydraulic circuit through said inlet passage but permit flow of hydraulic fluid into said circuit through said inlet passage when the pressure from the source exceeds the pressure in said circuit.
 79. A rotary machine as claimed in claim 77 wherein said drive means includes at least one drive member reciprocable in response to fluid flow to and from said cavity, and means responsive to reciprocation of said drive member to cause rotation of said shaft.
 80. A rotary machine as claimed in claim 79 wherein said means responsive to reciprocation of said drive member comprises an endless cam surface reacting against said drive member to impart rotation to said shaft upon reciprocation of said drive member.
 81. A rotary machine as claimed in claim 80 wherein said shaft is nonrotative with respective to said drive member such that the drive member rotates with the shaft.
 82. A rotary machine as claimed in claim 81 wherein the configuration of said cam surface causes the drive member to move in a sinusoidal path as the drive member rotates about the axis of said shaft.
 83. A rotary machine as claimed in claim 82 wherein said drive member reciprocates in a radial direction with respect to the axis of said shaft in response to fluid flow to and from said cavity.
 84. A rotary machine as claimed in claim 83 wherein the cam is formed with circumferentially spaced lobes projecting toward the axis of the shaft to define radially inwardly extending curved portions of the cam surface, said cam surface being formed with radially outwardly extending curved portions joining the radially inwardly extending portions of said lobes such that said drive member is radially extendable as it moves from a radially inward extending portion onto the adjacent radially outwardly extending portion, and is radially retractable as it moves from a radially outwardly extending portion to the adjacent radially inwardly extending portion as the drive member rotates about the axis of said shaft.
 85. A rotary machine as claimed in claim 84 wherein said drive member comprises a piston, and including an open ended cylinder carried by said shaft with said piston being received in the open end of said cylinder and projecting therefrom into engagement with same cam surface.
 86. A rotary machine as claimed in claim 85 wherein said cylinder is hydraulically connected with said cavity such that flow of fluid from said cavity to said cylinder urges the piston to radially extend, and return flow of fluid from said cylinder to said cavity permits the piston to radially retract.
 87. A rotary machine as claimed in claim 86 wherein said means cooperable with said drive means and responsive to oscillation of said rotors to cause hydraulic fluid to flow to and from said cavity comprises at least one hydraulic vane carried by each rotor and extending into said cavity such that the hydraulic vane of one rotor moves toward and away from the hydraulic vane of the other rotor in response to oscillation of the rotors to cause hydraulic fluid to flow to and from said cavity.
 88. A rotary machine as claimed in claim 87 wherein said shaft projects through said cavity.
 89. A rotary machine as claimed in claim 88 wherein each rotor includes a mounting ring, the hydraulic vane of each rotor projecting inwardly from the respective mounting ring toward the axis of said shaft.
 90. A rotary machine as claimed in claim 89 further including a pair of flywheels fixed to said shaft and spaced axially from each other and defining the end walls of said cavity.
 91. A rotary machine as claimed in claim 90 wherein the mounting rings of said rotors are disposed in end-to-end abutting relationship with the outer end of one of the rings engaging one of the flywheels and the outer end of the other ring engaging the other of the flywheels such that the abutting mounting rings define the outer cylindrical wall of said cavity.
 92. A rotary machine as claimed in claim 91 including an outer cylindrical wall defining an annular gas cavity with said ring members, the outer surfaces of said ring members defining the inner cylindrical wall of said annular gas cavity.
 93. A rotary machine as claimed in claim 92 including means forming a pair of axially spaced end walls for said gas cavity.
 94. A rotary machine as claimed in claim 93 wherein said gas cavity end walls are hollow to provide space for coolant.
 95. A rotary machine as claimed in claim 93 including at least one gas vane projecting from each of said ring members into sliding engagement with the inner surface of said outer cylindrical wall, each gas vane extending axially into sliding engagement with the end walls.
 96. A rotary machine comprising: a rotatable shaft; a pair of rotors each mounted for rotation with respect to said shaft; reciprocable drive members carried by said shaft and hydraulically connected with said rotors such that oscillation of the rotors with respect to each other causes reciprocation of the drive members; a reaction surface engaged by the drive members to provide a force to impart rotation to said shaft in response to reciprocation of said drive members and to constrain the drive members to move in a sinusoidal path about the axis of the shaft during rotation of the shaft, the hydraulic connection between the drive members and rotors constraining the rotors to oscillate with respect to each other with a symmetrical sine wave motion during rotation of the shaft.
 97. A rotary machine as claimed in claim 96 further including means defining a cavity for hydraulic fluid, and means in said cavity carried by said rotors operable to cause hydraulic fluid to flow to and from said cavity and cause reciprocation of said drive members in response to oscillation of said rotors.
 98. A rotary machine as claimed in claim 97 further including an inlet passage for connecting said hydraulic cavity with a source of hydraulic fluid under pressure; and a valve operable to prevent flow of hydraulic fluid from said hydraulic cavity through said inlet passage but permit flow of hydraulic fluid into said hydraulic cavity from said inlet passage when the pressure from the source exceeds the pressure in the hydraulic cavity.
 99. A rotary machine as claimed in claim 97 wherein said means in said cavity carried by said rotors comprise a plurality of hydraulic vanes movable relative to each other upon oscillation of said rotors to cause flow of hydraulic fluid to and from said cavity.
 100. A rotary machine as claimed in claim 99 wherein said plurality of hydraulic vanes comprises two sets of hydraulic vanes, one of which is carried by one of said rotors and the other of which is carried by the other of said rotors.
 101. A rotary machine as claimed in claim 100 wherein said shaft projects through said hydraulic cavity and is concentric with the inner wall thereof.
 102. A rotary machine as claimed in claim 101 further including a pair of flywheels fixed to said shaft and spaced axially from each other and defining the end walls of said hydraulic cavity.
 103. A rotary machine as claimed in claim 102 wherein each rotor includes a mounting ring, the hydraulic vanes of each rotor projecting radially inwardly from the respective mounting ring.
 104. A rotary machine as claimed in claim 103 wherein the mounting rings of said rotors are disposed in end-to-end abutting relationship with the outer end of one of said rings engaging onE of said end walls and the outer end of the other of said rings engaging the other of said end walls such that the abutting ring members define the outer cylindrical wall of said hydraulic cavity.
 105. A rotary machine as claimed in claim 104 wherein the hydraulic vanes of each rotor extend the full axial distance between the end walls such that a hydraulic vane of one rotor cooperates with an adjacent hydraulic vane of the other rotor to define the movable walls of an expansible and contractable chamber.
 106. A rotary machine as claimed in claim 105 including a port formed in at least one of said flywheels in communication with said expansible and contractable chamber such that contraction of the chamber causes fluid to flow from said cavity through said port and expansion of said chamber permits return flow of fluid through said port.
 107. A rotary machine as claimed in claim 106 wherein each set of hydraulic vanes includes four hydraulic vanes extending inwardly from the respective rings with the hydraulic vanes of each set being spaced 90* from each other on the respective ring and projecting radially inwardly to engage the outer surface of the shaft to thereby rotatably support the respective rotors on the shaft, each hydraulic vane of one set lying in said cavity between a pair of hydraulic vanes of the other set.
 108. A rotary machine as claimed in claim 107 wherein the hydraulic vanes cooperate to define eight segmental, expansible and contractable chambers in said cavity with each adjacent pair of hydraulic vanes defining the movable walls of one of said chambers wherein oscillation of said rotors causes one set of four of four of said chambers to expand while the other set of four of said chambers correspondingly contracts.
 109. A rotary machine as claimed in claim 108 further including means defining a passage for each of said chambers to conduct fluid flow to and from the chambers upon expansion and contraction, respectively, of the chambers.
 110. A rotary machine as claimed in claim 109 wherein said means defining a passage for each of said chambers includes one of said ports for each chamber in at least one of said flywheels.
 111. A rotary machine as claimed in claim 110 wherein said passage means further includes a recess in said shaft communicating with each of said ports.
 112. A rotary machine as claimed in claim 111 including at least one drive member for each of said chambers reciprocable in response to fluid flow to and from its associated chamber.
 113. A rotary machine as claimed in claim 112 further comprising at least one cam, said reaction surface comprising an endless cam surface in said cam.
 114. A rotary machine as claimed in claim 113 wherein said drive members are reciprocable in a radial direction with respect to the axis of said shaft.
 115. A rotary machine as claimed in claim 114 wherein the cam is formed with circumferentially spaced lobes projecting toward the axis of the shaft to define radially inwardly extending curved portions of the cam surface, said cam surface being formed with radially outwardly extending curved portions joining the radially inwardly extending portions of said lobes such that each of said drive members is radially extendable as it moves from a radially inwardly extending portion onto the adjacent radially outwardly extending portion, and is radially retractable as it moves from a radially outwardly extending portion to the adjacent radially inwardly extending portion as the drive member rotates about the axis of said shaft.
 116. A rotary machine as claimed in claim 115 wherein said drive members each comprises a ball piston, and including a plurality of open-ended cylinders carried by at least one of said flywheels, each of said pistons being received in the open end of one of said cylinders and projecting therefrom into engagement with said cam surface.
 117. A rotary machine as claimed in claim 116 wherein each of said ports connects one of said chambers with one of said cyliNders whereby each piston is radially extendable in response to contraction of its associated chamber to correspondingly increase the volume of its cylinder, subsequent expansion of the associated chamber permitting the piston to radially retract and correspondingly reduce the volume of its cylinder.
 118. A rotary machine as claimed in claim 117 including an outer cylindrical wall defining an annular gas cavity with said ring members, the outer surfaces of said ring members defining the inner cylindrical wall of said annular gas cavity.
 119. A rotary machine as claimed in claim 118 including means defining end walls for said annular gas cavity.
 120. A rotary machine as claimed in claim 119 including a plurality of gas vanes projecting from each of said ring members into sliding engagement with the inner surface of said outer cylindrical wall, each gas vane extending axially into sliding engagement with the end walls of the gas cavity.
 121. A rotary machine as claimed in claim 120 wherein each rotor has a gas vane for each hydraulic vane, the gas vanes each forming a radial extension of a hydraulic vane, each gas vane of one rotor extending axially between a pair of vanes of the other rotor such that eight segmental expansible and contractable gas chambers are formed in the annular gas cavity with each adjacent pair of gas vanes defining the movable wall of one of said gas chambers.
 122. A rotary machine as claimed in claim 121 further including a pair of spaced outer engine housing end walls, said shaft being rotatably mounted in said outer end walls and said outer cylindrical wall extending between said outer end walls.
 123. A rotary machine as claimed in claim 122 further including an annular groove formed in the inner surface of each said outer end walls, an inlet passage extending from the outer surface of said outer end wall for conducting hydraulic fluid to said annular groove, each of said cylinders having a check valve controlled port communicating with said annular groove whereby hydraulic fluid is supplied to each of the cylinders when the pressure in the annular groove exceeds the pressure in said cylinder.
 124. A rotary machine comprising: means defining an annular gas cavity having an outer cylindrical wall; a shaft; a pair of rotors each mounted for rotation with respect to said shaft and for oscillating rotation with respect to each other; at least one gas vane on each of said rotors projecting into said annular gas cavity such that an adjacent pair of gas vanes cooperate to define the movable walls of an expansible gas chamber, said pair of vanes approaching and receding from each other to respectively expand and contract the gas chamber in response to oscillation of the rotors with respect to each other as the rotors rotate about the axis of said shaft to respectively contract and expand the gas chamber formed therebetween; an external combustion chamber carried by said engine, said combustion chamber having an inlet port and an outlet port communicating with said annular gas cavity at circumferentially spaced locations such that the gas chamber sequentially (1) communicates with said combustion chamber when the space between the leading and trailing vanes is in communication with said inlet port only as the gas chamber approaches its contracted condition, (2) is disconnected from the combustion chamber when the trailing end of the leading vane and the leading end of the trailing vane are located between the inlet and outlet ports as the gas chamber reaches its fully retracted condition, and (3) communicates with said combustion chamber when the space between the leading and trailing vanes is in communication with said outlet port only as the gas chamber begins to expand from its fully retracted condition. 